The Basics

Written by the doctors and editors at UpToDate

What is type 2 diabetes?

This is a disorder that disrupts how the body uses sugar. It is sometimes called "type 2 diabetes mellitus."

All the cells in the body need sugar to work normally. Sugar gets into the cells with the help of a hormone called insulin. Insulin is made by the pancreas, an organ in the belly. If there is not enough insulin, or if cells in the body don't respond normally to insulin, sugar builds up in the blood. That is what happens to people with diabetes.

There are 2 different types of diabetes:

● In type 1 diabetes, the pancreas makes little or no insulin.

● In type 2 diabetes, the pancreas still makes some insulin, but the cells in the body stop responding normally. Eventually, the pancreas cannot make enough insulin to keep up.

Having excess body weight or obesity increases a person's risk of developing type 2 diabetes. But people without excess body weight can get diabetes, too.

What are the symptoms of type 2 diabetes?

Type 2 diabetes usually causes no symptoms.

When symptoms do happen, they include:

● Needing to urinate often

● Intense thirst

● Blurry vision

Can diabetes lead to other health problems?

Yes. Type 2 diabetes might not make you feel sick. But if it is not managed, it can lead to serious problems over time, such as:

● Heart attack

● Stroke

● Kidney disease

● Vision problems (or even blindness)

● Pain or loss of feeling in the hands and feet

● Needing to have fingers, toes, or other body parts removed (amputated)

Is there a test for type 2 diabetes?

Yes. To diagnose diabetes, your doctor or nurse can do a blood test. There are 2 tests for this. Both involve measuring the amount of sugar in your blood, called your "blood sugar" or "blood glucose":

● One of the tests measures your blood sugar at the time the blood sample is taken. This test is done in the morning. You can't eat or drink anything except water for at least 8 hours before the test.

● The other test shows what your average blood sugar has been for the past 2 to 3 months. This is called "hemoglobin A1C," or just "A1C." It can be checked at any time of the day, even if you have recently eaten.

How is type 2 diabetes treated?

The goals of treatment are to manage your blood sugar and lower the risk of future problems that can happen in people with diabetes.

Treatment might include:

● Lifestyle changes – This is an important part of managing diabetes. It includes:

● Eating healthy foods – In general, this means eating plenty of fruits, vegetables, whole grains, and low-fat dairy products. Limit or avoid sugary drinks and alcohol. If you take insulin before eating, you need to plan your meals carefully to know how much to take.

It might help to work with a dietitian (expert on food and eating). They can help make sure you get the nutrients you need.

● Getting plenty of physical activity – This usually means trying to be active for 30 to 60 minutes on most days of the week. Even gentle exercise, like walking, is good for your health.

● Medicines – Many medicines can help lower blood sugar. Some people need to take pills or get shots to help the body make more insulin or to help insulin do its job. Others need insulin shots.

Depending on your medicines, you might need to check your blood sugar regularly at home. But not everyone with type 2 diabetes needs to do this. Your doctor or nurse will tell you if you should be checking your blood sugar, and when and how to do this.

Sometimes, people with type 2 diabetes also need medicines to help prevent problems caused by the disease. For instance, medicines used to lower blood pressure can reduce the chances of a heart attack or stroke.

● General medical care – It's also important to take care of other areas of your health. This includes watching your blood pressure and cholesterol levels. You should also get certain vaccines, such as ones to protect against the flu and COVID-19. Some people also need a vaccine to prevent pneumonia.

Can type 2 diabetes be prevented?

Yes. To lower your chances of getting type 2 diabetes, the most important thing you can do is eat a healthy diet and get plenty of physical activity. This can help you lose weight if you have excess body weight. But eating well and being active are also good for your overall health.

If you smoke, quitting can also lower your risk of type 2 diabetes. Your doctor or nurse can help you quit.

All topics are updated as new evidence becomes available and our peer review process is complete.

This topic retrieved from UpToDate on: Apr 04, 2026.

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