What is Type 2 diabetes?
Type 2 diabetes is a disease where your body can’t use energy from food properly. Your pancreas produces insulin (a hormone) to help your cells use glucose (sugar). But over time your pancreas makes less insulin and the cells resist the insulin. This causes too much sugar to build up in your blood. High blood sugar levels from Type 2 diabetes can lead to serious health problems including heart disease, stroke or death.
Type 1 vs. Type 2 diabetes: What’s the difference?
Type 2 diabetes is not the same as Type 1 diabetes. In Type 1 diabetes, your pancreas doesn’t make any insulin. In Type 2, your pancreas doesn’t make enough insulin, and the insulin it is making doesn’t always work as it should. Both types are forms of diabetes mellitus, meaning they lead to hyperglycemia (high blood sugar).
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.
Who is at risk of developing Type 2 diabetes?
You’re more likely to develop Type 2 diabetes if you:
- Are Black, Hispanic, American Indian, Asian American or Pacific Islander.
- Are older than 45.
- Have overweight/obesity.
- Don’t exercise.
- Had gestational diabetes while pregnant.
- Have a family history of diabetes.
- Have high blood pressure.
- Have prediabetes (higher than normal blood sugar, though not high enough to be Type 2 diabetes).
How common is Type 2 diabetes?
Type 2 diabetes is the most common form of diabetes. About 1 in 10 Americans have the disease. It’s the 7th leading cause of death in the U.S.
Symptoms and Causes
What causes Type 2 diabetes?
Type 2 diabetes develops when the pancreas makes less insulin than the body needs, and the body cells stop responding to insulin. They don’t take in sugar as they should. Sugar builds up in your blood. When cells don’t respond to insulin, this is called insulin resistance. It's usually caused by:
- Lifestyle factors, including obesity and a lack of exercise.
- Genetics, or abnormal genes, that prevent cells from working as they should.
What are the symptoms of Type 2 diabetes?
Symptoms of Type 2 diabetes tend to develop slowly over time. They can include:
What are the complications of high blood sugar levels?
Potential complications of high blood sugar levels from Type 2 diabetes can include:
Rarely, Type 2 diabetes leads to a condition called diabetes-related ketoacidosis (DKA). DKA is a life-threatening condition that causes your blood to become acidic. People with Type 1 diabetes are more likely to have DKA.
Diagnosis and Tests
How is Type 2 diabetes diagnosed?
The following blood tests help your healthcare provider diagnose diabetes:
- Fasting plasma glucose test: checks your blood glucose level. This test is best done in the office in the morning after an eight hour fast (nothing to eat or drink except sips of water).
- Random plasma glucose test: This lab test can be done any time without the need to fast.
- Glycolated hemoglobin testing (A1c) measures your average blood sugar levels over three months.
- Oral glucose tolerance testing checks your blood sugar levels before and after you drink a sugary beverage. The test evaluates how your body handles glucose.
|Type of test||Diabetes (mg/dL)|
|Fasting glucose test||126 or higher|
|Random (anytime) |
|200 or higher|
|A1c test||6.5% or higher|
|Oral glucose |
|200 or higher|
Management and Treatment
How is Type 2 diabetes managed?
There’s no cure for Type 2 diabetes. But you can manage the condition by maintaining a healthy lifestyle and taking medication if needed. Work with your healthcare provider to manage your:
- Blood sugar: A blood glucose meter or continuous glucose monitoring (CGM) can help you meet your blood sugar target. Your healthcare provider may also recommend regular A1c tests, oral medications (pills), insulin therapy or injectable non-insulin diabetes medications.
- Blood pressure: Lower your blood pressure by not smoking, exercising regularly and eating a healthy diet. Your healthcare provider may recommend blood pressure medication such as beta blockers or ACE inhibitors.
- Cholesterol: Follow a meal plan low in saturated fats, trans fat, salt and sugar. Your healthcare provider may recommend statins, which are a type of drug to lower cholesterol.
What should a Type 2 diabetes meal plan include?
Ask your healthcare provider or a nutritionist to recommend a meal plan that’s right for you. In general, a Type 2 diabetes meal plans should include:
- Lean proteins: Proteins low in saturated fats include chicken, eggs and seafood. Plant-based proteins include tofu, nuts and beans.
- Minimally processed carbohydrates: Refined carbs like white bread, pasta and potatoes can cause your blood sugar to increase quickly. Choose carbs that cause a more gradual blood sugar increase such as whole grains like oatmeal, brown rice and whole-grain pasta.
- No added salt: Too much sodium, or salt, can increase your blood pressure. Lower your sodium by avoiding processed foods like those that come in cans or packages. Choose salt-free spices and use healthy oils instead of salad dressing.
- No added sugars: Avoid sugary foods and drinks, such as pies, cakes and soda. Choose water or unsweetened tea to drink.
- Non-starchy vegetables: These vegetables are lower in carbohydrates, so they don’t cause blood sugar spikes. Examples include broccoli, carrots and cauliflower.
Will I need medication or insulin for Type 2 diabetes?
Some people take medication to manage diabetes, along with diet and exercise. Your healthcare provider may recommend oral diabetes medications. These are pills or liquids that you take by mouth. For example, a medicine called metformin helps control the amount of glucose your liver produces.
You can also take insulin to help your body use sugar more efficiently. Insulin comes in the following forms:
- Injectable insulin is a shot you give yourself. Most people inject insulin into a fleshy part of their body such as their belly. Injectable insulin is available in a vial or an insulin pen.
- Inhaled insulin is inhaled through your mouth. It is only available in a rapid-acting form.
- Insulin pumps deliver insulin continuously, similar to how a healthy pancreas would. Pumps release insulin into your body through a tiny cannula (thin, flexible tube). Pumps connect to a computerized device that lets you control the dose and frequency of insulin.
How can I prevent Type 2 diabetes?
You can prevent or delay Type 2 diabetes by:
- Eating a healthy diet.
- Losing weight.
Regular checkups and screenings with your healthcare provider can also help you keep your blood sugar in check.
Outlook / Prognosis
What is the outlook for Type 2 diabetes?
If you have Type 2 diabetes, your outlook depends on how well you manage your blood glucose level. Untreated Type 2 diabetes can lead to a range of life-threatening health conditions. Diabetes requires lifelong management.
When should I call my doctor?
It’s important to monitor diabetes very closely if you’re sick. Even a common cold can be dangerous if it interferes with your insulin and blood sugar levels. Make a “sick day” plan with your healthcare provider so you know how often to check your blood sugar and what medications to take.
Contact your provider right away if you experience:
- Confusion or memory loss.
- Fever of 100°F or higher.
- High blood sugar for more than 24 hours.
- Nausea and vomiting for more than four hours.
- Problems with balance or coordination.
- Severe pain anywhere in your body.
- Trouble moving your arms or legs.
A note from Cleveland Clinic
Type 2 diabetes is a disease where your body doesn’t make enough insulin and can’t use sugar the way it should. Sugar, or glucose, builds up in your blood. High blood sugar can lead to serious health complications. But Type 2 diabetes is manageable. Regular exercise and a healthy diet can help you manage your blood sugar. You may also need medication or insulin. If you have Type 2 diabetes, you should monitor your blood sugar at home regularly and stay in close communication with your healthcare provider.
- American Diabetes Association. Type 2 Overview. (https://www.diabetes.org/diabetes/type-2) Accessed 3/1/2021.
- American Diabetes Association. Conquer High Blood Pressure. (https://www.diabetes.org/diabetes-risk/prevention/high-blood-pressure) Accessed 3/1/2021.
- Centers for Disease Control and Prevention. What is Diabetes? (https://www.cdc.gov/diabetes/basics/diabetes.html) Accessed 3/1/2021.
- Diabetes Food Hub. American Diabetes Association. What is the Diabetes Plate Method? (https://www.diabetesfoodhub.org/articles/what-is-the-diabetes-plate-method.html) Accessed 3/1/2021.
- MedlinePlus. Diabetes – when you are sick. (https://medlineplus.gov/ency/patientinstructions/000079.htm) Accessed 3/1/2021.
- National Institute of Diabetes and Digestive and Kidney Diseases. Diabetes. (https://www.niddk.nih.gov/health-information/diabetes) Accessed 3/1/2021.
Last reviewed by a Cleveland Clinic medical professional on 03/25/2021.