Type 2 Diabetes Overview

What is Type 2 Diabetes

Type 2 diabetes is a lifelong disease that prevents your body from using insulin the right way. People with type 2 diabetes are said to have insulin resistance.

It’s the most common type of diabetes. There are about 27 million people in the U.S. with type 2. Another 86 million have prediabetes: Their blood glucose is not normal, but not high enough to be diabetes yet.

Symptoms of Type 2 Diabetes

The symptoms of type 2 diabetes can be so mild you don't notice them. In fact, about 8 million people who have it don't know it. Symptoms include:

  • Being very thirsty
  • Peeing a lot
  • Blurry vision
  • Being cranky
  • Tingling or numbness in your hands or feet
  • Feeling worn out
  • Wounds that don't heal
  • Yeast infections that keep coming back

What Causes Type 2 Diabetes?

Your pancreas makes a hormone called insulin. It helps your cells turn glucose from the food you eat into energy. People with type 2 diabetes make insulin, but their cells don't use it as well as they should. Doctors call this insulin resistance.

At first, the pancreas makes more insulin to try to get glucose into your cells. But eventually it can't keep up, and the sugar builds up in your blood instead.

Usually a combination of things cause type 2 diabetes, including:

  • Genes. Scientists have found different bits of DNA that affect how your body makes insulin.
  • Extra weight. Being overweight or obese can cause insulin resistance, especially if you carry your extra pounds around the middle. Now, type 2 diabetes affects kids and teens as well as adults, mainly because of childhood obesity.
  • Metabolic syndrome. People with insulin resistance often have a group of conditions including high blood glucose, extra fat around the waist, high blood pressure, and high cholesterol and triglycerides.
  • Too much glucose from your liver. When your blood sugar is low, your liver makes and sends out glucose. After you eat, your blood sugar goes up, and usually the liver will slow down and store its glucose for later. But some people's livers don't. They keep cranking out sugar.
  • Bad communication between cells. Sometimes cells send the wrong signals or don't pick up messages correctly. When these problems affect how your cells make and use insulin or glucose, a chain reaction can lead to diabetes.
  • Broken beta cells. If the cells that make insulin send out the wrong amount of insulin at the wrong time, your blood sugar gets thrown off. High blood glucose can damage these cells, too.


What Are the Risk Factors for Diabetes?

While certain things make getting type 2 diabetes more likely, they won't give you the disease. But the more that apply to you, the higher your chances of getting it are. Some things, you can't control:

  • Age: 45 or older
  • Family: A parent, sister, or brother with diabetes
  • Ethnicity: African-American, Alaska Native, Native American, Asian-American, Hispanic or Latino, or Pacific Islander-American

Some things are related to your health and medical history. Your doctor may be able to help if you have:

Other things that raise your risk of diabetes have to do with your daily habits and lifestyle. These are the ones you can do something about:

Tips for Type 2 Diabetes Prevention

You can't change what happened in the past. Focus instead on what you can do now and going forward. Take medications and follow your doctor's suggestions to be healthy. Simple changes at home can make a big difference, too.

  • Lose weight. Dropping just 7% to 10% of your weight can cut your risk of type 2 diabetes in half.
  • Get active. Moving muscles use insulin. Thirty minutes of brisk walking a day will cut your risk by almost a third.
  • Eat right. Avoid highly processed carbs, sugary drinks, and trans and saturated fats. Limit red and processed meats.
  • Quit smoking. Work with your doctor to avoid gaining weight, so you don't create one problem by solving another.

Type 2 Diabetes: Tests for Diagnosis

Your doctor can test your blood for signs of type 2 diabetes. Usually, doctors will test you on two different days to confirm the diagnosis. But if your blood glucose is very high or you have many symptoms, one test may be all you need.

  • A1c: It's like an average of your blood glucose over the past 2 or 3 months.
  • Fasting plasma glucose: This measures your blood sugar on an empty stomach. You won't be able to eat or drink anything except water for 8 hours before the test.
  • Oral glucose tolerance test (OGTT): This checks your blood glucose before and 2 hours after you drink a sweet drink to see how your body handles the sugar.


Treatment for Type 2 Diabetes

Managing type 2 diabetes includes a mix of lifestyle changes and medication.

Lifestyle Changes

You may be able to reach your target blood sugar levels with diet and exercise alone.

  • Weight loss: Dropping extra pounds can help. While losing 5% to 10% of your body weight is good, losing 7% and keeping it off seems to be ideal. That means someone who weighs 180 pounds can change their blood sugar levels by losing around 13 pounds. Weight loss can seem overwhelming, but portion control and eating healthy foods are a good place to start.
  • Healthy eating: There’s no specific diet for type 2 diabetes. Instead, focus on:
    • Eating fewer calories
    • Cutting back on refined carbs, especially sweets
    • Adding more veggies and fruits to your diet
    • Getting more fiber
    • A registered dietitian can teach you about carbs and help you make a meal plan you can stick with.
  • Exercise: Try to get 30 to 60 minutes of physical activity every day. You can walk, bike, swim, or do anything else that gets your heart rate up. Pair that with strength training, like yoga or weightlifting. If you take a medication that lowers your blood sugar, you might need a snack before a workout.
  • Test your blood sugar: Depending on your treatment, especially if you’re on insulin, your doctor will tell you if you need to test your glucose levels and how often to do it.


If lifestyle changes don’t get you to your target blood sugar levels. You may need medication. Some of the most common for type 2 diabetes include:

  • Metformin (Fortamet, Glucophage, Glumetza, Riomet): This is usually the first medication used to treat type 2 diabetes. It lowers the amount of glucose your liver makes and helps your body respond better to the insulin it does make.
  • Sulfonylureas: This group of drugs help your body make more insulin. They include gliclazide (Diamicron, Dianorm), glimepride (Amaryl), glipizide (Glucotrol, Metaglip) and glyburide (DiaBeta, Micronase).
  • Meglitinides: They help your body make more insulin, and they work faster than sulfonylureas. You might take nateglinide (Starlix) or repaglinide (Prandin).
  • Thiazolidinediones: Like metformin, they make you more sensitive to insulin. You could get pioglitazone (Actos) or rosiglitazone (Avandia). But they also raise your risk of heart problems, so they aren’t usually a first choice for treatment.
  • DPP-4 inhibitors: These medications -- linagliptin (Tradjenta), saxagliptin (Onglyza), and sitagliptin (Januvia) -- help lower your blood sugar levels, but they also cause joint pain and could inflame your pancreas.
  • GLP-1 receptor agonists: You take these medications as a shot to slow digestion and lower blood sugar levels. Some of the most common ones are exenatide (Byetta, Bydureon), liraglutide (Victoza) and semaglutide (Ozempic).
  • SGLT2 inhibitors: These stop your kidneys from absorbing sugar into your bloodstream. But they can make heart attack or stroke more likely. You might get canagliflozin (Invokana), dapagliflozin (Farxiga), or empagliflozin (Jardiance).
  • Insulin: This used to be a medication of last resort for people with type 2 diabetes, but doctors often use insulin detemir (Levemir) or insulin glargine (Lantus) earlier now because it works so well. They’re long-lasting shots that you take at night.


Complications of Type 2 Diabetes

Over time, high blood sugar can damage and cause problems with your:

  • Heart and blood vessels
  • Kidneys
  • Eyes
  • Nerves, which can lead to trouble with digestion, the feeling in your feet, and your sexual response
  • Wound healing
  • Pregnancy

The best way to avoid these complications is to manage your type 2 diabetes well.

  • Take your diabetes medications or insulin on time.
  • Check your blood glucose.
  • Eat right, and don't skip meals.
  • See your doctor regularly to check for early signs of trouble.

WebMD Medical Reference Reviewed by Michael Dansinger, MD on June 12, 2019



American Diabetes Association: "Statistics About Diabetes," "Type 1 Diabetes," "Type 2," "Diagnosing Diabetes and Learning About Prediabetes."

U.S. National Library of Medicine: "Diabetes in Children and Teens."

Cleveland Clinic: "Diabetes Learning Module," "Preventing Diabetes Complications."

National Diabetes Information Clearinghouse: "Causes of Diabetes."

International Diabetes Federation: "Prevention," "Complications of Diabetes."

Harvard T.H. Chan School of Public Health: "Simple Steps to Preventing Diabetes."

National Institute of Diabetes and Digestive and Kidney Diseases: "Am I at risk for type 2 diabetes?"

Joslin Diabetes Center: "Common Questions About Type 2 Diabetes."

Carolinas HealthCare System: "Yeast Infections and Diabetes: What You Should Know."

Mayo Clinic: “Type 2 diabetes.”

LiverTox: “Second Generation Sulfonylureas.”

© 2019 WebMD, LLC. All rights reserved.