Type 2 Diabetes

Type 2 Diabetes Overview

Type 2 diabetes is the most common form of diabetes. It’s a chronic condition in which the body doesn’t make enough insulin, or doesn’t use it properly, leading to higher-than-normal blood sugar levels. Though you can develop type 2 diabetes at any age, it most commonly affects people ages 45 or older, those who have a family history of diabetes, or those who are overweight or obese.

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People with type 2 diabetes can't properly use or store glucose, either because their cells resist it or, in some cases, they don't make enough. Over time, glucose builds up in the bloodstream, which can lead to serious health complications unless people take steps to manage their blood sugar.

Type 2 diabetes is a common condition. Of the 34.2 million Americans with diabetes, up to 95% of those people have type 2 diabetes. (The other is Type 1 diabetes, an autoimmune condition that accounts for 1.6 million diagnoses in the US population.)

What Is It?

Essentially, diabetes means that your blood sugar level is too high. After you consume food or drink, that food is converted into glucose, which enters your bloodstream. Your pancreas, a digestive organ that produces the hormone insulin, then releases insulin into your bloodstream. Once there, insulin acts as the key that "unlocks" your cells, driving glucose in, where it can be used for the energy that fuels you.

Unfortunately, if you have type 2 diabetes, this insulin process doesn't work as efficiently as it should. For example, you may have insulin resistance—where these cells don't respond to insulin as they should. That means that these cells can't soak up the glucose they need. Your pancreas then compensates by making more insulin.

In the end, if your body can't make the amount of insulin it needs to move blood sugar out of your bloodstream and into your cells, your blood sugar (also known as blood glucose) levels will remain high. Overtime, this can lead to prediabetes and then type 2 diabetes. The consequences of diabetes include diabetic ketoacidosis (DKA), nerve damage called neuropathy, skin and foot infections, loss of vision, kidney disease, high blood pressure, and heart disease and stroke.


There are three main types of diabetes:

Type 1 diabetes: An autoimmune condition where your pancreas does not make insulin or makes very little insulin. This is typically diagnosed in younger people as children or teens. Treatment requires taking insulin via injection or continuous pump.

Type 2 diabetes: This type accounts for most cases of diabetes and is usually diagnosed in adults.

Prediabetes is when your blood sugar is elevated but not yet in the range for type 2 diabetes and affects one in three adults in the US. Prediabetes can be reversed through lifestyle changes.

Gestational diabetes. Occurs in about 10 percent of people who are pregnant and increases the risk of pregnancy complications. It is treatable with diet, exercise, and insulin injections, if necessary.


There are a wide range of symptoms of type 2 diabetes, though some people don't notice any changes with their health.

Symptoms include:


Unlike type 1 diabetes, which is not preventable, there are several lifestyle factors that contribute to the condition. You are more at risk for developing type 2 diabetes if:

Your weight is in the overweight or obese category on the BMI scale. Pay particular attention to where you're carrying this excess weight. A large waist circumference—more than 40 inches for men and more than 35 inches for women—correlates to the amount of visceral fat you have. This type of belly fat hugs your organs and is associated with type 2 diabetes, as well as heart disease.

You are sedentary. Exercise is great for blood sugar control. That's because when active, your muscle cells soak up the glucose in your bloodstream and convert that into the energy you need to move. This can help cells become more sensitive to insulin.

You have insulin resistance. If your cells cannot respond to insulin effectively, then your pancreas will push out more insulin. However, this process breaks down eventually, and your pancreas will no longer be able to produce the higher amounts of insulin needed. This will allow blood sugar to remain high.

Genes and family history. If members of your family have type 2 diabetes, you are more at risk for developing the condition.

Gestational diabetes. This type of diabetes occurs during pregnancy. Though it goes away after delivery, having gestational diabetes increases your risk of developing type 2 diabetes later in life.

Belonging to certain racial and ethnic groups: Type 2 diabetes is more common among:

  • African Americans
  • Alaska Natives
  • American Indians
  • Hispanics and Latinos
  • Native Hawaiians
  • Pacific Islanders


In order to diagnose type 2 diabetes, your doctor can use a few tests. All three are blood tests that measure your blood sugar levels in various ways. Your doctor may want to repeat these tests or do multiple to confirm a diagnosis.

Fasting plasma glucose (FPG) test. This test will be done in the morning. You should do this test after at least 8 hours of fasting, so you will skip breakfast prior to the test and only sip water. An FPG greater than or equal to 126 mg/dl indicates diabetes.

A1C test. This blood test measures your average blood sugar levels over the past three months. There are a few factors that may decrease the accuracy of results, such as if you have anemia or are a member of a certain racial/ethnic group, such as Southeast Asian descent. Ask your doctor if the A1C test is right for you.

Normal A1C levels are less than 5.7%. Prediabetes is 5.7% to 6.4%, and diabetes is diagnosed with an A1C of 6.5% or higher.

Random plasma glucose (RPG) test. This test does not require fasting, so doctors can order it at any time during the day. A reading off 200 mg/dl or greater indicates diabetes.


Diabetes is managed with healthy lifestyle changes. Some people may also require medications, like oral diabetes medications (sulfonylureas and Metformin are two) or injectable insulin. The goal is to bring blood sugar levels down and keep them in the healthy range.

Healthy diet. A diabetes-friendly diet is a heart-healthy diet focusing on fruit and vegetables, whole grains, lean proteins, and non-fat or low-fat dairy. The American Diabetes Association recommends following their Diabetes Plate Method, which suggests filling half of your plate with non-starchy vegetables, one-quarter with lean proteins (like chicken or fish), and one-quarter with carbohydrate foods (such as beans, grains, or starchy vegetables).

Exercise. Staying physically active has been shown to help control blood sugar levels. Aerobic exercise, such as walking or riding a bike, strength training, and generally adding in small bouts of activity throughout the day are all good options.

Weight loss. Losing a small amount of weight through diet and exercise can make it easier to manage your blood sugar.

Medication management. Work with your healthcare team to learn how to monitor your blood sugar and take medications as prescribed.


Nearly 90 million adults in the US have prediabetes, though about 84% have no idea that their blood sugar is in this higher-than-normal range. It's possible to stop prediabetes and prevent it from progressing into full-blown diabetes.

The best way? Through making shifts toward living a healthier lifestyle. These habits can also help if you have risk factors for type 2 diabetes but have normal blood sugar levels right now.

The National Diabetes Prevention Program offers a Lifestyle Change Program that pairs you with a health coach to help you successfully change your lifestyle. This includes counseling on adopting a heart-healthy diet, fitting in daily physical activity, and stress management. Some of the programs are free; some insurance plans may cover part or all. If you have prediabetes, losing just 5 to 10 percent of your weight can help delay or prevent diabetes. Quitting smoking is also important for healthy insulin function.

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