Type 1 Diabetes
What is Type 1 diabetes?
Insulin is an important hormone that regulates the amount of glucose (sugar) in your blood. Under normal circumstances, insulin functions in the following steps:
- Your body breaks down the food you eat into glucose (sugar), which is your body’s main source of energy.
- Glucose enters your bloodstream, which signals your pancreas to release insulin.
- Insulin helps glucose in your blood enter your muscle, fat and liver cells so they can use it for energy or store it for later use.
- When glucose enters your cells and the levels in your bloodstream decrease, it signals your pancreas to stop producing insulin.
If you don’t have enough insulin, too much sugar builds up in your blood, causing hyperglycemia (high blood sugar), and your body can’t use the food you eat for energy. This can lead to serious health problems or even death if it’s not treated. People with Type 1 diabetes need synthetic insulin every day in order to live and be healthy.
Type 1 diabetes was previously known as juvenile diabetes and insulin-dependent diabetes.
What is the difference between Type 1 diabetes and Type 2 diabetes?
In Type 2 diabetes (T2D), your pancreas doesn’t make enough insulin and/or your body doesn’t always use that insulin as it should — usually due to insulin resistance. Lifestyle factors, including obesity and a lack of exercise, can contribute to the development of Type 2diabetes as well as genetic factors.
In Type 1 diabetes, your pancreas doesn’t make any insulin. It’s caused by an autoimmune reaction.
Type 2 diabetes usually affects older adults, though it’s becoming more common in children. Type 1 diabetes usually develops in children or young adults, but people of any age can get it.
Type 2 diabetes is much more common than Type 1 diabetes.
Who does Type 1 diabetes affect?
Anyone at any age can develop Type 1 diabetes (T1D), though the most common age at diagnosis is between the ages of 4 to 6 and in early puberty (10 to 14 years).
In the United States, people who are non-Hispanic white are most likely to get Type 1 diabetes, and it affects people assigned female at birth and people assigned male at birth almost equally.
While you don’t have to have a family member with Type 1 diabetes to develop the condition, having a first-degree family member (parent or sibling) with Type 1 diabetes increases your risk of developing it.
How common is Type 1 diabetes?
Type 1 diabetes is relatively common. In the United States, approximately 1.24 million people live with Type 1 diabetes, and that number is expected to grow to five million by 2050.
Type 1 diabetes is one of the most common chronic diseases that affect children in the United States, though adults can be diagnosed with the disease as well.
Symptoms and Causes
What are the symptoms of Type 1 diabetes?
Symptoms of Type 1 diabetes typically start mild and get progressively worse or more intense, which could happen over several days, weeks or months. This is because your pancreas makes less and less insulin.
Symptoms of Type 1 diabetes include:
- Excessive thirst.
- Frequent urination, including frequent full diapers in infants and bedwetting in children.
- Excessive hunger.
- Unexplained weight loss.
- Blurred vision.
- Slow healing of cuts and sores.
- Vaginal yeast infections.
If you or your child has these symptoms, it’s essential to see your healthcare provider and ask to be tested for Type 1 diabetes as soon as possible. The sooner you’re diagnosed, the better.
If a diagnosis is delayed, untreated Type 1 diabetes can be life-threatening due to a complication called diabetes-related ketoacidosis (DKA). Seek emergency medical care if you or your child are experiencing any combination of the following symptoms:
- Fruity-smelling breath.
- Nausea and vomiting.
- Abdominal (stomach) pain.
- Rapid breathing.
- Loss of consciousness.
What causes Type 1 diabetes?
Type 1 diabetes develops when your immune system mistakenly attacks and destroys cells in your pancreas that make insulin. This destruction can happen over months or years, ultimately resulting in a total lack (deficiency) of insulin.
Although scientists don’t yet know the exact cause of Type 1 diabetes, they believe there’s a strong genetic component. The risk of developing the disease with no family history is approximately 0.4%. If your biological mother has Type 1 diabetes, your risk is 1% to 4%, and your risk is 3% to 8% if your biological father has it. If both of your biological parents have Type 1 diabetes, your risk of developing the condition is as high as 30%.
Scientists believe that certain factors, such as a virus or environmental toxins, can trigger your immune system to attack cells in your pancreas if you have a genetic predisposition for developing Type 1 diabetes.
Diagnosis and Tests
How is Type 1 diabetes diagnosed?
Type 1 diabetes is relatively simple to diagnose. If you or your child has symptoms of Type 1 diabetes, your healthcare provider will order the following tests:
- Blood glucose test: Your healthcare provider uses a blood glucose test to check the amount of sugar in your blood. They may ask you to do a random test (without fasting) and a fasting test (no food or drink for at least eight hours before the test). If the result shows that you have very high blood sugar, it typically means you have Type 1 diabetes.
- Glycosylated hemoglobin test (A1c): If blood glucose test results indicate that you have diabetes, your healthcare provider may do an A1c test. This measures your average blood sugar levels over three months.
- Antibody test: This blood test checks for autoantibodies to determine if you have Type 1 or Type 2 diabetes. Autoantibodies are proteins that attack your body’s tissue by mistake. The presence of certain autoantibodies means you have Type 1 diabetes. Autoantibodies usually aren’t present in people who have Type 2 diabetes.
Your provider will also likely order the following tests to assess your overall health and to check if you have diabetes-related ketoacidosis, a serious acute complication of undiagnosed or untreated Type 1 diabetes:
- Basic metabolic panel: This is a blood sample test that measures eight different substances in your blood. The panel provides helpful information about your body's chemical balance and metabolism.
- Urinalysis: A urinalysis (also known as a urine test) is a test that examines the visual, chemical and microscopic aspects of your urine (pee). Providers use it to measure several different aspects of your urine. In the case of a Type 1 diagnosis, they’ll likely order the test to check for ketones, which is a substance your body releases when it has to break down fat for energy instead of using glucose. A high amount of ketones causes your blood to become acidic, which can be life-threatening.
- Arterial blood gas: An arterial blood gas (ABG) test is a blood test that requires a sample from an artery in your body to measure the levels of oxygen and carbon dioxide in your blood.
Management and Treatment
What kind of doctor treats Type 1 diabetes?
An endocrinologist — a healthcare provider who specializes in treating hormone-related conditions — treats people who have Type 1 diabetes. Some endocrinologists specialize in diabetes.
If your child has Type 1 diabetes, they’ll need to see a pediatric endocrinologist.
You’ll need to see your endocrinologist regularly to ensure that your Type 1 diabetes management is working well. Your insulin needs will change throughout your life.
How is Type 1 diabetes treated?
People with Type 1 diabetes need synthetic insulin every day, multiple times a day in order to live and be healthy. They also need to try to keep their blood sugar within a healthy range.
Since several factors affect your blood sugar level, Type 1 diabetes management is complex and highly individualized.
Three of the main components of Type 1 diabetes management include:
- Blood glucose (sugar) monitoring.
- Carbohydrate counting.
Insulin for Type 1 diabetes management
There are several different types of synthetic insulin. They each start to work at different speeds, and they last in your body for different lengths of time. You may need to use more than one type.
Some types of inulin are more expensive than others. Work with your endocrinologist to find the right type of insulin for your needs.
The amount of insulin you need throughout the day depends on several factors including:
- Your weight.
- Your age.
- Your physical activity level.
- The types of food you eat.
- Your blood sugar (glucose) level at any given time.
Along with a background level of insulin (often called a basal rate), you’ll need to give yourself specific amounts of insulin when you eat and to correct high blood sugar levels.
You can take insulin in the following ways:
- Multiple daily injections (MDI): Injectable insulin uses a vial and syringe. With each injection, you use a syringe to get the correct dose of insulin out of the vial. You can inject the insulin into the fatty tissue of your belly, upper arm, thigh or buttocks. Injections are usually the least expensive way to take insulin.
- Pen: Insulin pens are similar to injections, but the pen is pre-filled with insulin. The disposable pen needles are usually more convenient than syringes. They can also be a good option for people with low vision.
- Pump: Insulin pumps are devices that deliver insulin continuously and on demand. They mimic the way your pancreas would naturally release insulin. Pumps deliver insulin through a tiny catheter (thin, flexible tube) that goes in your belly or another fleshy area of your body.
- Rapid-acting inhaled insulin: This type of insulin (known as Afrezza®) is inhaled through your mouth (much like an asthma inhaler). It works much quicker than other types of insulin.
The amount of insulin you need day to day will vary across your lifespan and under specific circumstances. For example, you typically need larger doses of insulin during puberty, pregnancy and when you’re taking steroid medication.
Because of this, it’s important to see your endocrinologist regularly — usually at least three times a year —to make sure your insulin dosages and overall diabetes management are working for you.
Blood sugar monitoring for Type 1 diabetes management
People with Type 1 diabetes need to monitor their blood sugar closely throughout the day. Maintaining a healthy blood sugar range is the best way to avoid health complications. You can monitor your blood sugar in the following ways:
- Blood glucose meter: You prick your finger and put a small drop of blood on the meter’s test strip. Your blood glucose level appears on the meter within seconds. A blood glucose meter is usually the least expensive home testing option, but it only reports your blood sugar at the time of the check.
- Continuous glucose monitoring (CGM): There are different types of CGMs. Most CGMs require you to insert a small sensor under your skin at home every seven to 14 days. Some CGMs are implanted by a healthcare provider. The sensor continuously records your blood glucose levels. People using a CGM require fewer finger sticks. CGM systems can be more expensive than fingerstick blood glucose meters, but they provide much more information about your glucose levels, including where they have been and where they are going. You can set different alarms to alert you if your blood sugar is trending too low or too high.
Your healthcare provider will tell you what your target blood glucose level range should be. It depends on a variety of factors, including your:
- Overall health.
- Access to diabetes technology and supplies.
Carb counting for Type 1 diabetes management
A large part of Type 1 diabetes management is counting carbohydrates (carbs) in the food and drinks you consume in order to give yourself proper doses of insulin.
Carbohydrates are a type of macronutrient found in certain foods and drinks, such as grains, sweets, legumes and milk. When your body digests foods and drinks that contain carbs, it turns them into glucose, which is your body’s preferred form of energy. This raises your blood sugar level.
Because of this, people with Type 1 diabetes need to give themselves insulin doses when they consume carbohydrates.
Carb counting at its basic level involves counting the number of grams of carbohydrate in a meal (through reading nutrition labels) and matching that to your dose of insulin.
You’ll use what's known as an insulin-to-carb ratio to calculate how much insulin you should take in order to manage your blood sugars when eating. Insulin-to-carb rations vary from person to person and may even be different at different times of the day. Your endocrinologist will help you determine your insulin-to-carb ratio.
What are the side effects of diabetes treatment?
The main side effect of diabetes treatment through insulin is low blood sugar (hypoglycemia). Low blood sugar can occur if you take too much insulin based on your food intake and/or activity level. Hypoglycemia is usually considered to be below 70 mg/dL (milligrams per decilitre).
Symptoms of low blood sugar can start quickly, with people experiencing them in different ways. The signs of hypoglycemia are unpleasant, but they provide good warnings that you should take action before your blood sugar drops more.
The symptoms of low blood sugar include:
- Shaking or trembling.
- Sweating and chills.
- Dizziness or lightheadedness.
- Faster heart rate.
- Nervousness or irritability.
- Pale skin.
- Restless sleep.
Hypoglycemia can be dangerous and needs to be treated right away.
The American Diabetes Association recommends the “15-15 rule” for an episode of low blood sugar, which involves:
- Eating or drinking 15 grams of carbohydrates to raise your blood sugar.
- After 15 minutes, check your blood sugar.
- If it’s still below 70 mg/dL, have another 15 grams of carbs.
- Repeat until your blood sugar is at least 70 mg/dL.
If you have symptoms of hypoglycemia but can’t test your blood sugar, use the 15-15 rule until you feel better.
Children typically need fewer grams of carbs to treat lows. Check with their healthcare provider.
Is there a cure for Type 1 diabetes?
There is currently no cure for Type 1 diabetes, but scientists are working on ways to prevent or slow down the progression of the condition through studies such as TrialNet.
Scientists are also working on research into pancreatic islet transplantation — an experimental treatment for people who have brittle diabetes.
Pancreatic islets are clusters of cells in the pancreas that make insulin. Your immune system attacks these cells in Type 1 diabetes. A pancreatic islet transplant replaces destroyed islets with new ones that make and release insulin. This procedure takes islets from the pancreas of an organ donor and transfers them to a person with Type 1 diabetes. Because researchers are still studying pancreatic islet transplantation, the procedure is only available to people enrolled in a study.
Is Type 1 diabetes preventable?
Unfortunately, there’s nothing you can do to prevent developing Type 1 diabetes.
Since Type 1 diabetes can run in families, your healthcare provider can test your family members for the autoantibodies that cause the disease. Type 1 Diabetes TrialNet, an international research network, also offers autoantibody testing to family members of people with Type 1 diabetes.
The presence of autoantibodies, even without diabetes symptoms, means you’re more likely to develop Type 1 diabetes. If you have a sibling, child or parent with Type 1 diabetes, you may want to get an autoantibody test. These tests can help catch Type 1 diabetes in its earliest phases.
Outlook / Prognosis
What is the prognosis (outlook) for Type 1 diabetes?
Type 1 diabetes is a challenging condition to manage properly, especially consistently throughout your lifetime. Because of this, T1D is associated with several complications. Close to 50% of people with Type 1 diabetes will develop a serious complication over their lifetime. Some may lose eyesight while others may develop end-stage kidney disease.
For those who reach the first 20 years after diagnosis without any complications, the prognosis (outlook) is good.
What are the complications of Type 1 diabetes?
Since your blood touches virtually every part of your body, having poorly managed Type 1 diabetes that results in continuous high blood sugar (hyperglycemia) can damage several different areas of your body.
Potential complications of Type 1 diabetes include:
- Eye problems, such as diabetes-related retinopathy diabetes-related macular edema, cataracts and glaucoma.
- Foot problems, including ulcers and infections that can lead to gangrene.
- Heart disease.
- High blood pressure.
- Kidney disease.
- Oral health problems.
- Diabetes-related neuropathy (nerve damage).
- Skin conditions, such as dry skin, bacterial and fungal infections and diabetes-related dermopathy.
How do I take care of myself if I have Type 1 diabetes?
Type 1 diabetes is a complex condition that requires daily management, effort and planning. Some tips that can help you manage your Type 1 diabetes include:
- Check your blood sugar often: Checking your blood sugar with a glucometer and/or using a continuous glucose monitor (CGM) is crucial to managing diabetes and preventing complications. Try to at least check your blood sugar before and after meals and before you go to sleep. It’s important to treat high blood sugar as soon as possible.
- Take your insulin and other medication regularly: Follow your healthcare provider’s instructions for taking your insulin and other medications (if applicable).
- See your endocrinologist regularly: It’s important to see your endocrinologist regularly to be sure that your Type 1 diabetes management plan is working. Don’t be afraid to ask them specific questions.
- See your other providers regularly, especially your eye doctor: Type 1 diabetes can cause complications in various areas of your body, but especially your eyes. It’s important to see your eye doctor (ophthalmologist) at least yearly so that they can check the health of your eyes.
- Have a sick day plan: Talk with your endocrinologist about how to take care of yourself and manage your diabetes when you’re sick. Since illness can trigger diabetes-related ketoacidosis (DKA), it’s important to know what to do if you get sick before it happens so that you’re prepared.
- Stay educated: Don’t be afraid to ask your provider questions about Type 1 diabetes. The more you know about Type 1 diabetes your diabetes management, the more likely you’ll be able to live healthily and prevent complications.
- Find community: Connecting with other people who have Type 1 diabetes — whether in-person or online — can help you feel less alone in living with and managing diabetes.
- Take care of your mental health: People with diabetes are two to three times more likely to have depression and are 20% more likely to be diagnosed with anxiety than those without diabetes. Living with a chronic condition that requires constant care can be overwhelming. It’s important to talk to a mental health professional if you’re experiencing signs of depression and/or anxiety.
How do I take care of my child who has Type 1 diabetes?
When your child is first diagnosed with Type 1 diabetes, it can be overwhelming. There’s a lot to learn, and you’ll need to get up to speed quickly on how to manage Type 1 diabetes and incorporate lifestyle changes at home. Caregivers often manage Type 1 diabetes for their children, especially if they’re young.
Some things you’ll need to do include:
- Learn to count carbohydrates, which may involve adapting your family’s diet.
- Learn about how insulin works and how to give shots or use an insulin pump.
- Learn to check your child’s blood sugar and interpret the results.
- Understand how different foods, exercise and illnesses affect blood sugar levels.
- Manage rivalries and feelings of jealousy between your children (if you have more than one), which is common when there’s a Type 1 diabetes diagnosis in a family.
- Support your child’s mental and emotional health and reach out for professional help if needed. They may suddenly feel very overwhelmed with what’s happening or feel that they’re different from their peers.
- Help your child learn how to listen to their body for symptoms of high and low blood sugar and how to manage Type 1 diabetes on their own (when age-appropriate).
- Educate friends, family, school administrators and others about Type 1 diabetes and your child’s management needs and what they can do to help. It’s important to reach out for help because while you can (and will) do a lot for your child, you can’t do it all.
When should I see my healthcare provider if I have Type 1 diabetes?
If you or your child are experiencing symptoms of Type 1 diabetes, such as extreme thirst and frequent urination, see your healthcare provider as soon as possible.
If you or your child have been diagnosed with diabetes, you’ll need to see your endocrinologist multiple times a year throughout your life to make sure your diabetes management is working well for you.
When should I go to ER if I have Type 1 diabetes?
If you’re experiencing symptoms of diabetes-related ketoacidosis (DKA), such as high blood sugar, nausea and vomiting and rapid breathing, get to the nearest emergency room (ER) as soon as possible. DKA is life-threatening and requires immediate medical care.
A note from Cleveland Clinic
Being diagnosed with Type 1 diabetes is a life-changing event, but it doesn’t mean that you can’t live a happy and healthy life. Type 1 diabetes involves constant day-to-day care and management. While it’ll likely be very overwhelming at first, over time you’ll get a better grasp on how to manage the condition and how to be in tune with your body.
Be sure to see your endocrinologist and other healthcare providers regularly. Managing Type 1 diabetes involves a team effort — you’ll want both medical professionals and friends and family on your side. Don’t be afraid to reach out to them if you need help.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy