Diabetes: An Overview

Overview

What is diabetes?

Diabetes happens when your body isn't able to take up sugar (glucose) into its cells and use it for energy. This results in a build up of extra sugar in your bloodstream.

Poorly controlled diabetes can lead to serious consequences, causing damage to a wide range of your body's organs and tissues – including your heart, kidneys, eyes and nerves.

Why is my blood glucose level high? How does this happen?

The process of digestion includes breaking down the food you eat into various different nutrient sources. When you eat carbohydrates (for example, bread, rice, pasta), your body breaks this down into sugar (glucose). When glucose is in your bloodstream, it needs help – a "key" – to get into its final destination where it's used, which is inside your body's cells (cells make up your body's tissues and organs). This help or "key" is insulin.

Insulin is a hormone made by your pancreas, an organ located behind your stomach. Your pancreas releases insulin into your bloodstream. Insulin acts as the “key” that unlocks the cell wall “door,” which allows glucose to enter your body’s cells. Glucose provides the “fuel” or energy tissues and organs need to properly function.

If you have diabetes:

  • Your pancreas doesn’t make any insulin or enough insulin.

Or

  • Your pancreas makes insulin but your body’s cells don’t respond to it and can’t use it as it normally should.

If glucose can’t get into your body’s cells, it stays in your bloodstream and your blood glucose level rises.

What are the different types of diabetes?

The types of diabetes are:

  • Type 1 diabetes: This type is an autoimmune disease, meaning your body attacks itself. In this case, the insulin-producing cells in your pancreas are destroyed. Up to 10% of people who have diabetes have Type 1. It’s usually diagnosed in children and young adults (but can develop at any age). It was once better known as “juvenile” diabetes. People with Type 1 diabetes need to take insulin every day. This is why it is also called insulin-dependent diabetes.
  • Type 2 diabetes: With this type, your body either doesn’t make enough insulin or your body’s cells don’t respond normally to the insulin. This is the most common type of diabetes. Up to 95% of people with diabetes have Type 2. It usually occurs in middle-aged and older people. Other common names for Type 2 include adult-onset diabetes and insulin-resistant diabetes. Your parents or grandparents may have called it “having a touch of sugar.”
  • Prediabetes: This type is the stage before Type 2 diabetes. Your blood glucose levels are higher than normal but not high enough to be officially diagnosed with Type 2 diabetes.
  • Gestational diabetes: This type develops in some women during their pregnancy. Gestational diabetes usually goes away after pregnancy. However, if you have gestational diabetes you're at higher risk of developing Type 2 diabetes later on in life.

Less common types of diabetes include:

  • Monogenic diabetes syndromes: These are rare inherited forms of diabetes accounting for up to 4% of all cases. Examples are neonatal diabetes and maturity-onset diabetes of the young.
  • Cystic fibrosis-related diabetes: This is a form of diabetes specific to people with this disease.
  • Drug or chemical-induced diabetes: Examples of this type happen after organ transplant, following HIV/AIDS treatment or are associated with glucocorticoid steroid use.

Diabetes insipidus is a distinct rare condition that causes your kidneys to produce a large amount of urine.

How common is diabetes?

Some 34.2 million people of all ages – about 1 in 10 – have diabetes in the U.S. Some 7.3 million adults aged 18 and older (about 1 in 5) are unaware that they have diabetes (just under 3% of all U.S. adults). The number of people who are diagnosed with diabetes increases with age. More than 26% of adults age 65 and older (about 1 in 4) have diabetes.

Who gets diabetes? What are the risk factors?

Factors that increase your risk differ depending on the type of diabetes you ultimately develop.

Risk factors for Type 1 diabetes include:

  • Having a family history (parent or sibling) of Type 1 diabetes.
  • Injury to the pancreas (such as by infection, tumor, surgery or accident).
  • Presence of autoantibodies (antibodies that mistakenly attack your own body’s tissues or organs).
  • Physical stress (such as surgery or illness).
  • Exposure to illnesses caused by viruses.

Risk factors for prediabetes and Type 2 diabetes include:

  • Family history (parent or sibling) of prediabetes or Type 2 diabetes.
  • Being African-American, Hispanic, Native American, Asian-American race or Pacific Islander.
  • Being overweight.
  • Having high blood pressure.
  • Having low HDL cholesterol (the “good” cholesterol) and high triglyceride level.
  • Being physically inactive.
  • Being age 45 or older.
  • Having gestational diabetes or giving birth to a baby weighing more than 9 pounds.
  • Having polycystic ovary syndrome.
  • Having a history of heart disease or stroke.
  • Being a smoker.

Risk factors for gestational diabetes include:

  • Family history (parent or sibling) of prediabetes or Type 2 diabetes.
  • Being African-American, Hispanic, Native American or Asian-American.
  • Being overweight before your pregnancy.
  • Being over 25 years of age.

Symptoms and Causes

What causes diabetes?

The cause of diabetes, regardless of the type, is having too much glucose circulating in your bloodstream. However, the reason why your blood glucose levels are high differs depending on the type of diabetes.

  • Causes of Type 1 diabetes: This is an immune system disease. Your body attacks and destroys insulin-producing cells in your pancreas. Without insulin to allow glucose to enter your cells, glucose builds up in your bloodstream. Genes may also play a role in some patients. Also, a virus may trigger the immune system attack.
  • Cause of Type 2 diabetes and prediabetes: Your body’s cells don't allow insulin to work as it should to let glucose into its cells. Your body's cells have become resistant to insulin. Your pancreas can’t keep up and make enough insulin to overcome this resistance. Glucose levels rise in your bloodstream.
  • Gestational diabetes: Hormones produced by the placenta during your pregnancy make your body’s cells more resistant to insulin. Your pancreas can’t make enough insulin to overcome this resistance. Too much glucose remains in your bloodstream.

What are the symptoms of diabetes?

Symptoms of diabetes include:

  • Increased thirst.
  • Weak, tired feeling.
  • Blurred vision.
  • Numbness or tingling in the hands or feet.
  • Slow-healing sores or cuts.
  • Unplanned weight loss.
  • Frequent urination.
  • Frequent unexplained infections.
  • Dry mouth.

Other symptoms

Type 1 diabetes symptoms: Symptoms can develop quickly – over a few weeks or months. Symptoms begin when you’re young – as a child, teen or young adult. Additional symptoms include nausea, vomiting or stomach pains and yeast infections or urinary tract infections.

Type 2 diabetes and prediabetes symptoms: You may not have any symptoms at all or may not notice them since they develop slowly over several years. Symptoms usually begin to develop when you’re an adult, but prediabetes and Type 2 diabetes is on the rise in all age groups.

Gestational diabetes: You typically will not notice symptoms. Your obstetrician will test you for gestational diabetes between 24 and 28 weeks of your pregnancy.

What are the complications of diabetes?

If your blood glucose level remains high over a long period of time, your body’s tissues and organs can be seriously damaged. Some complications can be life-threatening over time.

Complications include:

Complications of gestational diabetes:

In the mother: Preeclampsia (high blood pressure, excess protein in urine, leg/feet swelling), risk of gestational diabetes during future pregnancies and risk of diabetes later in life.

In the newborn: Higher-than-normal birth weight, low blood sugar (hypoglycemia), higher risk of developing Type 2 diabetes over time and death shortly after birth.

Diagnosis and Tests

How is diabetes diagnosed?

Diabetes is diagnosed and managed by checking your glucose level in a blood test. There are three tests that can measure your blood glucose level: fasting glucose test, random glucose test and A1c test.

  • Fasting plasma glucose test: This test is best done in the morning after an eight hour fast (nothing to eat or drink except sips of water).
  • Random plasma glucose test: This test can be done any time without the need to fast.
  • A1c test: This test, also called HbA1C or glycated hemoglobin test, provides your average blood glucose level over the past two to three months. This test measures the amount of glucose attached to hemoglobin, the protein in your red blood cells that carries oxygen. You don’t need to fast before this test.
  • Oral glucose tolerance test: In this test, blood glucose level is first measured after an overnight fast. Then you drink a sugary drink. Your blood glucose level is then checked at hours one, two and three.

Type of testNormal
(mg/dL)
Prediabetes
(mg/dL)
Diabetes
(mg/dL)
Fasting
glucose test

Less than 100

100-125126 or higher
Random (anytime)
glucose test

Less than 140

140-199200 or higher
A1c test

Less than 5.7%

5.7 - 6.4%6.5% or higher
Oral glucose
tolerance test
Less than 140140-199200 or higher

Gestational diabetes tests: There are two blood glucose tests if you are pregnant. With a glucose challenge test, you drink a sugary liquid and your glucose level is checked one hour later. You don’t need to fast before this test. If this test shows a higher than normal level of glucose (over 140 ml/dL), an oral glucose tolerance test will follow (as described above).

Type 1 diabetes: If your healthcare provider suspects Type 1 diabetes, blood and urine samples will be collected and tested. The blood is checked for autoantibodies (an autoimmune sign that your body is attacking itself). The urine is checked for the presence of ketones (a sign your body is burning fat as its energy supply). These signs indicate Type 1 diabetes.

Who should be tested for diabetes?

If you have symptoms or risk factors for diabetes, you should get tested. The earlier diabetes is found, the earlier management can begin and complications can be lessened or prevented. If a blood test determines you have prediabetes, you and your healthcare professional can work together to make lifestyle changes (e.g. weight loss, exercise, healthy diet) to prevent or delay developing Type 2 diabetes.

Additional specific testing advice based on risk factors:

  • Testing for Type 1 diabetes: Test in children and young adults who have a family history of diabetes. Less commonly, older adults may also develop Type 1 diabetes. Therefore, testing in adults who come to the hospital and are found to be in diabetic ketoacidosis is important. Ketoacidosis a dangerous complication that can occur in people with Type 1 diabetes.
  • Testing for type 2 diabetes: Test adults age 45 or older, those between 19 and 44 who are overweight and have one or more risk factors, women who have had gestational diabetes, children between 10 and 18 who are overweight and have at least two risk factors for type 2 diabetes.
  • Gestational diabetes: Test all pregnant women who have had a diagnosis of diabetes. Test all pregnant women between weeks 24 and 28 of their pregnancy. If you have other risk factors for gestational diabetes, your obstetrician may test you earlier.

Management and Treatment

How is diabetes managed?

Diabetes affects your whole body. To best manage diabetes, you’ll need to take steps to keep your risk factors under control and within the normal range, including:

  • Keep your blood glucose levels as near to normal as possible by following a diet plan, taking prescribed medication and increasing your activity level.
  • Maintain your blood cholesterol (HDL and LDL levels) and triglyceride levels as near the normal ranges as possible.
  • Control your blood pressure. Your blood pressure should not be over 140/90 mmHg.

You hold the keys to managing your diabetes by:

  • Planning what you eat and following a healthy meal plan. Follow a Mediterranean diet (vegetables, whole grains, beans, fruits, healthy fats, low sugar) or Dash diet. These diets are high in nutrition and fiber and low in fats and calories. See a registered dietitian for help understanding nutrition and meal planning.
  • Exercising regularly. Try to exercise at least 30 minutes most days of the week. Walk, swim or find some activity you enjoy.
  • Losing weight if you are overweight. Work with your healthcare team to develop a weight-loss plan.
  • Taking medication and insulin, if prescribed, and closely following recommendations on how and when to take it.
  • Monitoring your blood glucose and blood pressure levels at home.
  • Keeping your appointments with your healthcare providers and having laboratory tests completed as ordered by your doctor.
  • Quitting smoking (if you smoke).

You have a lot of control – on a day-to-day basis – in managing your diabetes!

How do I check my blood glucose level? Why is this important?

Checking your blood glucose level is important because the results help guide decisions about what to eat, your physical activity and any needed medication and insulin adjustments or additions.

The most common way to check your blood glucose level is with a blood glucose meter. With this test, you prick the side of your finger, apply the drop of blood to a test strip, insert the strip into the meter and the meter will show your glucose level at that moment in time. Your healthcare provider will tell you how often you’ll need to check your glucose level.

What is continuous glucose monitoring?

Advancements in technology have given us another way to monitor glucose levels. Continuous glucose monitoring uses a tiny sensor inserted under your skin. You don't need to prick your finger. Instead, the sensor measures your glucose and can display results anytime during the day or night. Ask your healthcare provider about continuous glucose monitors to see if this is an option for you.

What should my blood glucose level be?

Ask your healthcare team what your blood glucose level should be. They may have a specific target range for you. In general, though, most people try to keep their blood glucose levels at these targets:

  • Before a meal: between 80 and 130 mg/dL.
  • About two hours after the start of a meal: less than 180 mg/dL.

What happens if my blood glucose level is low?

Having a blood glucose level that is lower than the normal range (usually below 70 mg/dL) is called hypoglycemia. This is a sign that your body gives out that you need sugar.

Symptoms you might experience if you have hypoglycemia include:

  • Weakness or shaking.
  • Moist skin, sweating.
  • Fast heartbeat.
  • Dizziness.
  • Sudden hunger.
  • Confusion.
  • Pale skin.
  • Numbness in mouth or tongue.
  • Irritability, nervousness.
  • Unsteadiness.
  • Nightmares, bad dreams, restless sleep.
  • Blurred vision.
  • Headaches, seizures.

You might pass out if your hypoglycemia is not managed.

What happens if my blood glucose level is high?

If you have too much glucose in your blood, you have a condition called hyperglycemia. Hyperglycemia is defined as:

  • A blood glucose level greater than 125 mg/dL while in the fasting state (nothing to eat or drink for at least eight hours).

or

  • A blood glucose level greater than 180 mg/dL one to two hours after eating.

How is diabetes treated?

Treatments for diabetes depend on your type of diabetes, how well controlled your blood glucose level is and your other existing health conditions.

  • Type 1 diabetes: If you have this type, you must take insulin every day. Your pancreas no longer makes insulin.
  • Type 2 diabetes: If you have this type, your treatments can include medications (both for diabetes and for conditions that are risk factors for diabetes), insulin and lifestyle changes such as losing weight, making healthy food choices and being more physically active.
  • Prediabetes: If you have prediabetes, the goal is to keep you from progressing to diabetes. Treatments are focused on treatable risk factors, such as losing weight by eating a healthy diet (like the Mediterranean diet) and exercising (at least five days a week for 30 minutes). Many of the strategies used to prevent diabetes are the same as those recommended to treat diabetes (see prevention section of this article).
  • Gestational diabetes: If you have this type and your glucose level is not too high, your initial treatment might be modifying your diet and getting regular exercise. If the target goal is still not met or your glucose level is very high, your healthcare team may start medication or insulin.

Oral medications and insulin work in one of these ways to treat your diabetes:

  • Stimulates your pancreas to make and release more insulin.
  • Slows down the release of glucose from your liver (extra glucose is stored in your liver).
  • Blocks the breakdown of carbohydrates in your stomach or intestines so that your tissues are more sensitive to (better react to) insulin.
  • Helps rid your body of glucose through increased urination.

What oral medications are approved to treat diabetes?

Over 40 medications have been approved by the Food and Drug Administration for the treatment of diabetes. It’s beyond the scope of this article to review all of these drugs. Instead, we’ll briefly review the main drug classes available, how they work and present the names of a few drugs in each class. Your healthcare team will decide if medication is right for you. If so, they’ll decide which specific drug(s) are best to treat your diabetes.

Diabetes medication drug classes include:

  • Sulfonylureas: These drugs lower blood glucose by causing the pancreas to release more insulin. Examples include glimepiride (Amaryl®), glipizide (Glucotrol®) and glyburide (Micronase®, DiaBeta®).
  • Glinides (also called meglitinides): These drugs lower blood glucose by getting the pancreas to release more insulin. Examples include repaglinide (Prandin®) and nateglinide (Starlix®).
  • Biguanides: These drugs reduce how much glucose the liver produces. It also improves how insulin works in the body, and slows down the conversion of carbohydrates into sugar. Metformin (Glucophage®) is the example.
  • Alpha-glucosidase inhibitors: These drugs lower blood glucose by delaying the breakdown of carbohydrates and reducing glucose absorption in the small intestine. An example is acarbose (Precose®).
  • Thiazolidinediones: These drugs improve the way insulin works in the body by allowing more glucose to enter into muscles, fat and the liver. Examples include pioglitazone (Actos®) and rosiglitazone (Avandia®).
  • GLP-1 analogs (also called incretin mimetics or glucagon-like peptide-1 receptor agonists): These drugs increase the release of insulin, reduce glucose release from the liver after meals and delay food emptying from the stomach. Examples include exenatide (Byetta®), liraglutide (Victoza®), albiglutide (Tanzeum®), semaglutide (Rybelsus®) and dulaglutide (Trulicity®).
  • DPP-4 inhibitors (also called dipeptidyl peptidase-4 inhibitors): These drugs help your pancreas release more insulin after meals. They also lower the amount of glucose released by the liver. Examples include alogliptin (Nesina®), sitagliptin (Januvia®), saxagliptin (Onglyza®) and linagliptin (Tradjenta®).
  • SGLT2 inhibitors (also called sodium-glucose cotransporter 2 inhibitors): These drugs work on your kidneys to remove glucose in your body through your urine. Examples include canagliflozin (Invokana®), dapagliflozin (Farxiga®) and empagliflozin (Jardiance®).
  • Bile acid sequestrants: These drugs lower cholesterol and blood sugar levels. Examples include colestipol (Colestid®), cholestyramine (Questran®) and colesevelam (Welchol®).
  • Dopamine agonist: This medication lowers the amount of glucose released by the liver. An example is bromocriptine (Cyclocet®).

Many oral diabetes medications may be used in combination or with insulin to achieve the best blood glucose control. Some of the above medications are available as a combination of two medicines in a single pill. Others are available as injectable medications, for example, the GLP-1 agonist semaglutide (Ozempic®) and lixisenatide (Adlyxin®).

Always take your medicine exactly as your healthcare prescribes it. Discuss your specific questions and concerns with them.

What insulin medications are approved to treat diabetes?

There are many types of insulins for diabetes. If you need insulin, you healthcare team will discuss the different types and if they are to be combined with oral medications. To follow is a brief review of insulin types.

  • Rapid-acting insulins: These insulins are taken 15 minutes before meals, they peak (when it best lowers blood glucose) at one hour and work for another two to four hours. Examples include insulin glulisine (Apidra®), insulin lispro (Humalog®) and insulin aspart (NovoLog®).
  • Short-acting insulins: These insulins take about 30 minutes to reach your bloodstream, reach their peak effects in two to three hours and last for three to six hours. An example is insulin regular (Humulin R®).
  • Intermediate-acting insulins: These insulins reach your bloodstream in two to four hours, peak in four to 12 hours and work for up to 18 hours. An example in NPH.
  • Long-acting insulins: These insulins work to keep your blood sugar stable all day. Usually, these insulins last for about 18 hours. Examples include insulin glargine (Basaglar®, Lantus®, Toujeo®), insulin detemir (Levemir®) and insulin degludec (Tresiba®).

There are insulins that are a combination of different insulins. There are also insulins that are combined with a GLP-1 receptor agonist medication (e.g. Xultophy®, Soliqua®).

How is insulin taken? How many different ways are there to take insulin?

Insulin is available in several different formats. You and your healthcare provider will decide which delivery method is right for you based on your preference, lifestyle, insulin needs and insurance plan. Here’s a quick review of available types.

  • Needle and syringe: With this method, you’ll insert a needle into a vial of insulin, pull back the syringe and fill the needle with the proper dose of insulin. You’ll inject the insulin into your belly or thigh, buttocks or upper arm – rotating the injection spots. You may need to give yourself one or more shots a day to maintain your target blood glucose level.
  • Insulin pen: This device looks like a pen with a cap. They come prefilled with insulin or with insulin cartridges that are inserted and replaced after use.
  • Insulin pump: Insulin pumps are small, computerized devices, about the size of a small cell phone that you wear on your belt, in your pocket, or under your clothes. They deliver rapid-acting insulin 24 hours a day through a small flexible tube called a cannula. The cannula is inserted under the skin using a needle. The needle is then removed leaving only the flexible tube under the skin. You replaces the cannula every two to three days. Another type of insulin pump is attached directly to your skin and does not use tubes.
  • Artificial pancreas (also called a closed loop insulin delivery system): This system uses an insulin pump linked to a continuous glucose monitor. The monitor checks your blood glucose levels every five minutes and then the pump delivers the needed dose of insulin.
  • Insulin inhaler: Inhalers allow you to breath in powdered inhaler through an inhaler device that you insert into your mouth. The insulin is inhaled into your lungs, then absorbed into your bloodstream. Inhalers are only approved for use by adults with Type 1 or Type 2 diabetes.
  • Insulin injection port: This delivery method involves the placement of a short tube into tissue beneath your skin. The port is held in place with an adhesive patch. You use a needle and syringe or insulin pen and inject the insulin through this port. The port is changed every few days. The port provides a single site for injection instead of having to rotate injection sites.
  • Jet injector: This is a needleless delivery method that uses high pressure to send a fine spray of insulin through your skin.

Are there other treatment options for diabetes?

Yes. There are two types of transplantations that might be an option for a select number of patients who have Type 1 diabetes. A pancreas transplant is possible. However, getting an organ transplant requires taking immune-suppressing drugs for the rest of your life and dealing with the side effects of these drugs. However, if the transplant is successful, you’ll likely be able to stop taking insulin.

Another type of transplant is a pancreatic islet transplant. In this transplant, clusters of islet cells (the cells that make insulin) are transplanted from an organ donor into your pancreas to replace those that have been destroyed.

Another treatment under research for Type 1 diabetes is immunotherapy. Since Type 1 is an immune system disease, immunotherapy holds promise as a way to use medication to turn off the parts of the immune system that cause Type 1 disease.

Bariatric surgery is another treatment option that’s an indirect treatment for diabetes. Bariatric surgery is an option if you have Type 2 diabetes, are obese (body mass index over 35) and considered a good candidate for this type of surgery. Much improved blood glucose levels are seen in people who have lost a significant amount of weight.

Of course other medications are prescribed to treat any existing health problems that contribute to increasing your risk of developing diabetes. These conditions include high blood pressure, high cholesterol and other heart-related diseases.

Prevention

Can prediabetes, Type 2 diabetes and gestational diabetes be prevented?

Although diabetes risk factors like family history and race can’t be changed, there are other risk factors that you do have some control over. Adopting some of the healthy lifestyle habits listed below can improve these modifiable risk factors and help to decrease your chances of getting diabetes:

  • Eat a healthy diet, such as the Mediterranean or Dash diet. Keep a food diary and calorie count of everything you eat. Cutting 250 calories per day can help you lose ½ pound per week.
  • Get physically active. Aim for 30 minutes a day at least five days a week. Start slow and work up to this amount or break up these minutes into more doable 10 minute segments. Walking is great exercise.
  • Lose weight if you are overweight. Don’t lose weight if you are pregnant, but check with your obstetrician about healthy weight gain during your pregnancy.
  • Lower your stress. Learn relaxation techniques, deep breathing exercises, mindful meditation, yoga and other helpful strategies.
  • Limit alcohol intake. Men should drink no more than two alcoholic beverages a day; women should drink no more than one.
  • Get an adequate amount of sleep (typically 7 to 9 hours).
  • Quit smoking.
  • Take medications – to manage existing risk factors for heart disease (e.g., high blood pressure, cholesterol) or to reduce the risk of developing Type 2 diabetes – as directed by your healthcare provider.
  • If you think you have symptoms of prediabetes, see your provider.

Can Type 1 diabetes be prevented?

No. Type 1 diabetes is an autoimmune disease, meaning your body attacks itself. Scientists aren’t sure why someone’s body would attack itself. Other factors may be involved too, such as genetic changes.

Can the long-term complications of diabetes be prevented?

Chronic complications are responsible for most illness and death associated with diabetes. Chronic complications usually appear after several years of elevated blood sugars (hyperglycemia). Since patients with Type 2 diabetes may have elevated blood sugars for several years before being diagnosed, these patients may have signs of complications at the time of diagnosis.

The complications of diabetes have been described earlier in this article. Although the complications can be wide ranging and affect many organ systems, there are many basic principles of prevention that are shared in common. These include:

  • Take your diabetes medications (pills and/or insulin) as prescribed by your doctor.
  • Take all of your other medications to treat any risk factors (high blood pressure, high cholesterol, other heart-related problems and other health conditions) as directed by your doctor.
  • Monitor your blood sugars closely.
  • Follow a healthy diet, such as the Mediterranean or Dash diet. Do not skip meals.
  • Exercise regularly, at least 30 minutes five days a week.
  • Lose weight if you are overweight.
  • Keep yourself well-hydrated (water is your best choice).
  • Quit smoking, if you smoke.
  • See your doctor regularly to monitor your diabetes and to watch for complications.

Outlook / Prognosis

What should I expect if I have been diagnosed with diabetes?

If you have diabetes, the most important thing you can do is keep your blood glucose level within the target range recommended by your healthcare provider. In general, these targets are:

  • Before a meal: between 80 and 130 mg/dL.
  • About two hours after the start of a meal: less than 180 mg/dL.

You will need to closely follow a treatment plan, which will likely include following a customized diet plan, exercising 30 minutes five times a week, quitting smoking, limiting alcohol and getting seven to nine hours of sleep a night. Always take your medications and insulin as instructed by your provider.

Living With

When should I call my doctor?

If you haven’t been diagnosed with diabetes, you should see your healthcare provider if you have any symptoms of diabetes. If you already have been diagnosed with diabetes, you should contact your provider if your blood glucose levels are outside of your target range, if current symptoms worsen or if you develop any new symptoms.

Does eating sugary foods cause diabetes?

Sugar itself doesn't directly cause diabetes. Eating foods high in sugar content can lead to weight gain, which is a risk factor for developing diabetes. Eating more sugar than recommended – American Heart Association recommends no more than six teaspoons a day (25 grams) for women and nine teaspoons (36 grams) for men – leads to all kinds of health harms in addition to weight gain.

These health harms are all risk factors for the development of diabetes or can worsen complications. Weight gain can:

  • Raise blood pressure, cholesterol and trigelyceride levels.
  • Increase your risk of cardiovascular disease.
  • Cause fat buildup in your liver.
  • Cause tooth decay.

What types of healthcare professionals might be part of my diabetes treatment team?

Most people with diabetes see their primary healthcare provider first. Your provider might refer you to an endocrinologist/pediatric endocrinologist, a physician who specializes in diabetes care. Other members of your healthcare team may include an ophthalmologist (eye doctor), nephrologist (kidney doctor), cardiologist (heart doctor), podiatrist (foot doctor), neurologist (nerve and brain doctor), gastroenterologist (digestive tract doctor), registered dietician, nurse practitioners/physician assistants, diabetes educator, pharmacist, personal trainer, social worker, mental health professional, transplant team and others.

How often do I need to see my primary diabetes healthcare professional?

In general, if you are being treated with insulin shots, you should see your doctor at least every three to four months. If you are treated with pills or are managing diabetes through diet, you should be seen at least every four to six months. More frequent visits may be needed if your blood sugar is not controlled or if complications of diabetes are worsening.

Can diabetes be cured or reversed?

Although these seem like simple questions, the answers are not so simple. Depending on the type of your diabetes and its specific cause, it may or may not be possible to reverse your diabetes. Successfully reversing diabetes is more commonly called achieving “remission.”

Type 1 diabetes is an immune system disease with some genetic component. This type of diabetes can’t be reversed with traditional treatments. You need lifelong insulin to survive. Providing insulin through an artificial pancreas (insulin pump plus continuous glucose monitor and computer program) is the most advanced way of keeping glucose within a tight range at all times – most closely mimicking the body. The closest thing toward a cure for Type 1 is a pancreas transplant or a pancreas islet transplant. Transplant candidates must meet strict criteria to be eligible. It’s not an option for everyone and it requires taking immunosuppressant medications for life and dealing with the side effects of these drugs.

It’s possible to reverse prediabetes and Type 2 diabetes with a lot of effort and motivation. You’d have to reverse all your risk factors for disease. To do this means a combination of losing weight, exercising regularly and eating healthy (for example, a plant-based, low carb, low sugar, healthy fat diet). These efforts should also lower your cholesterol numbers and blood pressure to within their normal range. Bariatric surgery (surgery that makes your stomach smaller) has been shown to achieve remission in some people with Type 2 diabetes. This is a significant surgery that has its own risks and complications.

If you have gestational diabetes, this type of diabetes ends with the birth of your child. However, having gestational diabetes is a risk factor for developing Type 2 diabetes.

The good news is that diabetes can be effectively managed, treated and controlled. The extent to which your Type 1 or Type 2 diabetes can be controlled is a discussion to have with your healthcare provider.

Can diabetes kill you?

Yes, it’s possible that if diabetes remains undiagnosed and uncontrolled (severely high or severely low glucose levels) it can cause devastating harm to your body. Diabetes can cause heart attack, heart failure, stroke, kidney failure and coma. These complications can lead to your death. Cardiovascular disease in particular is the leading cause of death in adults with diabetes.

Frequently Asked Questions

How does COVID-19 affect a person with diabetes?

Although having diabetes may not necessarily increase your risk of contracting COVID-19, if you do get the virus, you are more likely to have more severe complications. If you contract COVID-19, your blood sugars are likely to increase as your body is working to clear the infection. If you contract COVID-19, contact your healthcare team early to let them know.

How does diabetes affect your heart, eyes, feet, nerves and kidneys?

Blood vessels are located throughout our body’s tissues and organs. They surround our body’s cells, providing a transfer of oxygen, nutrients and other substances, using blood as the exchange vehicle. In simple terms, diabetes doesn’t allow glucose (the body’s fuel) to get into cells and it damages blood vessels in/near these organs and those that nourish nerves. If organs, nerves and tissues can’t get the essentials they need to properly function, they can begin to fail.“Proper function” means that your heart’s blood vessels, including arteries, are not damaged (narrowed or blocked). In your kidneys, this means that waste products can be filtered out of your blood. In your eyes, this means that the blood vessels in your retina (area of your eye that provides your vision) remain intact. In your feet and nerves, this means that nerves are nourished and that there’s blood flow to your feet. Diabetes causes damage that prevents proper function.

How does diabetes lead to amputation?

Uncontrolled diabetes can lead to poor blood flow (poor circulation). Without oxygen and nutrients (delivered in blood), you are more prone to the development of cuts and sores that can lead to infections that can’t fully heal. Areas of your body that are farthest away from your heart (the blood pump) are more likely to experience the effects of poor blood flow. So areas of your body like your toes, feet, legs and fingers are more likely to be amputated if infection develops and healing is poor.

Can diabetes cause blindness?

Yes. Because uncontrolled diabetes can damage the blood vessels of the retina, blindness is possible. If you haven’t been diagnosed with diabetes yet but are experiencing a change in your vision, see primary healthcare provider or ophthalmologist as soon as you can.

Can diabetes cause hearing loss?

Scientists don’t have firm answers yet but there appears to be a correlation between hearing loss and diabetes. According to the American Diabetes Association, a recent study found that hearing loss was twice as common in people with diabetes versus those who didn’t have diabetes. Also, the rate of hearing loss in people with prediabetes was 30% higher compared with those who had normal blood glucose levels. Scientists think diabetes damages the blood vessels in the inner ear, but more research is needed.

Can diabetes cause headaches or dizziness?

Yes, it’s possible to develop headaches or dizziness if your blood glucose level is too low – usually below 70 mg/dL. This condition is called hypoglycemia. You can read about the other symptoms hypoglycemia causes in this article.Hypoglycemia is common in people with Type 1 diabetes and can happen in some people with Type 2 diabetes who take insulin (insulin helps glucose move out of the blood and into your body’s cells) or medications such as sulfonylureas.

Can diabetes cause hair loss?

Yes, it’s possible for diabetes to cause hair loss. Uncontrolled diabetes can lead to persistently high blood glucose levels. This, in turn, leads to blood vessel damage and restricted flow, and oxygen and nutrients can’t get to the cells that need it – including hair follicles. Stress can cause hormone level changes that affect hair growth. If you have Type 1 diabetes, your immune system attacks itself and can also cause a hair loss condition called alopecia areata.

What types of diabetes require insulin?

People with Type 1 diabetes need insulin to live. If you have Type 1 diabetes, your body has attacked your pancreas, destroying the cells that make insulin. If you have Type 2 diabetes, your pancreas makes insulin, but it doesn’t work as it should. In some people with Type 2 diabetes, insulin may be needed to help glucose move from your bloodstream to your body’s cells where it’s needed for energy. You may or may not need insulin if you have gestational diabetes. If you are pregnant or have Type 2 diabetes, your healthcare provider will check your blood glucose level, assess other risk factors and determine a treatment approach – which may include a combination of lifestyle changes, oral medications and insulin. Each person is unique and so is your treatment plan.

Can you be born with diabetes? Is it genetic?

You aren’t born with diabetes, but Type 1 diabetes usually appears in childhood. Prediabetes and diabetes develop slowly over time – years. Gestational diabetes occurs during pregnancy.Scientists do believe that genetics may play a role or contribute to the development of Type 1 diabetes. Something in the environment or a virus may trigger its development. If you have a family history of Type 1 diabetes, you are at higher risk of developing Type 1 diabetes. If you have a family history of prediabetes, Type 2 diabetes or gestational diabetes, you’re at increased risk of developing prediabetes, Type 2 diabetes or gestational diabetes.

What is diabetic ketoacidosis?

Diabetic ketoacidosis is a life-threatening condition. It happens when your liver breaks down fat to use as energy because there’s not enough insulin and therefore glucose isn’t being used as an energy source. Fat is broken down by the liver into a fuel called ketones. The formation and use of ketones is a normal process if it has been a long time since your last meal and your body needs fuel. Ketones are a problem when your fat is broken down too fast for your body to process and they build up in your blood. This makes your blood acidic, which is a condition called ketoacidosis. Diabetic ketoacidosis can be the result of uncontrolled Type 1 diabetes and less commonly, Type 2 diabetes.Diabetic ketoacidosis is diagnosed by the presence of ketones in your urine or blood and a basic metabolic panel. The condition develops over several hours and can cause coma and possibly even death.

What is hyperglycemic hyperosmolar nonketotic syndrome (HHNS)?

Hyperglycemic hyperosmolar nonketotic syndrome (HHNS) develops more slowly (over days to weeks) than diabetic ketoacidosis. It occurs in patients with Type 2 diabetes, especially the elderly and usually occurs when patients are ill or stressed.If you have HHNS, you blood glucose level is typically greater than 600 mg/dL. Symptoms include frequent urination, drowsiness, lack of energy and dehydration. HHNS is not associated with ketones in the blood. It can cause coma or death. You’ll need to be treated in the hospital.

What does it mean if test results show I have protein in my urine?

This means your kidneys are allowing protein to be filtered through and now appear in your urine. This condition is called proteinuria. The continued presence of protein in your urine is a sign of kidney damage.

A note from Cleveland Clinic

There’s much you can do to prevent the development of diabetes (except Type 1 diabetes). However, if you or your child or adolescent develop symptoms of diabetes, see your healthcare provider. The earlier diabetes is diagnosed, the sooner steps can be taken to treat and control it. The better you are able to control your blood sugar level, the more likely you are to live a long, healthy life.

Last reviewed by a Cleveland Clinic medical professional on 03/28/2021.

References

  • Centers for Disease Control and Prevention. . Accessed 3/15/2021.National Diabetes Statistics Report 2020 (https://www.cdc.gov/diabetes/pdfs/data/statistics/national-diabetes-statistics-report.pdf)
  • National Institute of Diabetes and Digestive and Kidney Diseases. . Accessed 3/15/2021.Diabetes (https://www.niddk.nih.gov/health-information/diabetes)
  • Centers for Disease Control and Prevention. . Accessed 3/15/2021.Diabetes (https://www.cdc.gov/diabetes/index.html)
  • American Diabetes Association. . Accessed 3/15/2021.Diabetes Overview (https://www.diabetes.org/diabetes)
  • The American College of Obstetricians and Gynecologists. . Accessed 3/15/2021.Gestational Diabetes (https://www.acog.org/womens-health/faqs/gestational-diabetes?utm_source=redirect&utm_medium=web&utm_campaign=otn)
  • American Diabetes Association. . Accessed 3/15/2021.Diabetes and Hearing Loss (https://www.diabetes.org/diabetes-and-hearing-loss)
  • American Diabetes Association. . Accessed 3/15/2021.Learn the Genetics of Diabetes (https://www.diabetes.org/diabetes/genetics-diabetes)
  • Joslin Diabetes Center. . Accessed 3/15/2021.Patient Care (https://www.joslin.org/patient-care)
  • DiabetesUK.Diabetes.co.uk. . Accessed 3/15/2021.Reversing Type 2 Diabetes (https://www.diabetes.co.uk/reversing-diabetes.html)
  • DiabetesUK.Diabetes.co.uk. . Accessed 3/15/2021.Type 2 diabetes: What to do if you’re at risk (https://www.diabetes.org.uk/resources-s3/migration/pdf/KYR%2520Booklet.pdf)
  • American Heart Association. . Accessed 3/15/2021.Cardiovascular disease and diabetes (https://www.heart.org/en/health-topics/diabetes/why-diabetes-matters/cardiovascular-disease--diabetes)
  • American Heart Association. . Accessed 3/15/2021.The Diabetic Diet (https://www.heart.org/en/health-topics/diabetes/prevention--treatment-of-diabetes/the-diabetic-diet)
  • American Diabetes Association. . Accessed 3/15/2021.How COVID-19 Impacts People with Diabetes (https://www.diabetes.org/coronavirus-covid-19/how-coronavirus-impacts-people-with-diabetes)
  • StatPearls. . Accessed 3/15/2021.Diabetes Mellitus (https://www.statpearls.com/articlelibrary/viewarticle/20429/)
  • American Diabetes Association. . Diabetes Care 2010 Jan;33(Suppl 1) S62-S69. Accessed 3/15/2021.Diabetes and Classification of Diabetes Mellitus (https://care.diabetesjournals.org/content/33/Supplement_1/S62)
  • American Diabetes Association. . Accessed 3/15/2021.Eating right doesn’t have to be boring (https://www.diabetes.org/healthy-living/recipes-nutrition)
  • Merck Manual Consumer Version. . Accessed 3/15/2021.Diabetes Mellitus (DM) (https://www.merckmanuals.com/home/hormonal-and-metabolic-disorders/diabetes-mellitus-dm-and-disorders-of-blood-sugar-metabolism/diabetes-mellitus-dm?query=diabetes)
  • JDRF. . Accessed 3/15/2021.Type 1 Diabetes Resources (https://www.jdrf.org/)
  • Makin V, Lansang C. Diabetes management: Beyond hemoglobin A. Cleve Clinic J Med 2019;86(9):595-600. Accessed 3/15/2021.
  • Miller E, Aguilar RB, Herman ME, Schwartz SS. Evolving concepts and treatment. Cleve Clinic J Med 2019;86(7):494-504. Accessed 3/15/2021.
  • Skugor M. Medical treatment of diabetes mellitus. Cleve Clinic J Med 2017;84(7 suppl 1):S57-S61. Accessed 3/15/2021.
  • American Association of Clinical Endocrinologists. . Accessed 3/15/2021.About Diabetes (https://www.aace.com/disease-and-conditions/diabetes)

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