The three main types of diabetes are type 1, type 2, and gestational diabetes. Depending on your type, your body may not produce enough or any insulin, or it may not be able to use produced insulin properly.

When any of these things happen, the body is unable to get sugar from the blood into your cells. This can lead to high blood sugar levels.

Glucose, the form of sugar found in your blood, is one of your main energy sources. A lack of insulin or a resistance to insulin causes sugar to build up in your blood. This can lead to health problems.

Read on to learn more about three main types of diabetes.

Type 1 diabetes

Type 1 diabetes is believed to be an autoimmune condition. This means your immune system mistakenly attacks and destroys the beta cells in your pancreas that produce insulin. The damage is permanent.

What prompts the attacks is not clear. There may be both genetic and environmental reasons. Lifestyle factors are not believed to play a role.

Type 2 diabetes

Type 2 diabetes starts out as insulin resistance. This means your body cannot use insulin efficiently, which causes your pancreas to produce more insulin until it cannot keep up with demand. Insulin production then decreases, which causes high blood sugar.

The exact cause of type 2 diabetes is unknown. Contributing factors may include:

  • genetics
  • a more sedentary lifestyle
  • higher weight or obesity

There may also be other health factors and environmental reasons.

Gestational diabetes

Gestational diabetes is caused by insulin-blocking hormones that are produced during pregnancy.

This type of diabetes only happens during pregnancy. It is often seen in people with preexisting prediabetes and a family history of diabetes.

About 50 percent of people diagnosed with gestational diabetes go on to develop type 2 diabetes.

General symptoms of unmanaged diabetes include:

Type 2 diabetes can cause discolored patches in the folds of skin in your armpits and neck. Since type 2 diabetes usually takes longer to diagnose, you may feel more symptoms at the time of diagnosis, like pain or numbness in your feet.

Type 1 diabetes often develops more quickly and can cause symptoms like weight loss or a condition called diabetic ketoacidosis. Diabetic ketoacidosis can occur when you have very high blood sugar but little or no insulin in your body.

Symptoms of both types of diabetes can appear at any age, but type 1 usually appears in children and young adults.

Type 2 typically appears in people over the age of 45. But younger people are increasingly being diagnosed with type 2 diabetes due to sedentary lifestyles and an increase in weight.

About 37.3 million people in the United States have diabetes. About 5 to 10 percent have type 1 diabetes, while 90 to 95 percent have type 2 diabetes.

Another 84.1 million people are thought to have prediabetes. But most people with prediabetes do not know they have the condition.

Prediabetes occurs when your blood glucose is higher than it should be but not high enough to be diabetes.

You’re more likely to develop diabetes if you have a family history of the disease.

Other risk factors for type 2 diabetes include:

  • having a sedentary lifestyle
  • living with extra weight or obesity
  • having had gestational diabetes or prediabetes

Complications of diabetes generally develop over time. Having poorly managed blood sugar levels increases the risk of serious complications that can become life threatening.

Chronic complications include:

  • vessel disease, which can lead to heart attack or stroke
  • eye problems (retinopathy)
  • infection or skin conditions
  • nerve damage (neuropathy)
  • kidney damage (nephropathy)
  • amputations due to neuropathy or vessel disease

Type 2 diabetes may increase the risk of developing Alzheimer’s disease, especially if your blood sugar is not well managed.

Complications in pregnancy

High blood sugar levels during pregnancy can increase the risk of:

No matter what type of diabetes you have, you’ll need to work closely with your doctor to manage it.

The main goal is to keep blood glucose levels within your target range. Your doctor will let you know what your target range should be. Targets vary with the type of diabetes, age, and presence of complications.

If you have gestational diabetes, your blood sugar targets will be lower than people with other types of diabetes.

Physical activity is an important part of diabetes management. Ask your doctor how many minutes per week you should devote to aerobic exercise. Diet is also important.

You’ll also need to monitor your blood pressure and cholesterol.

Treating type 1

All people with type 1 diabetes must take insulin to live since damage to the pancreas is permanent. There are different types of insulin available with different times of onset, peak, and duration.

Insulin is injected just under the skin. Your doctor will show you how to properly inject and rotate injection sites. You can also use an insulin pump, which is a device worn outside your body that can be programmed to release a specific dose.

There are now continuous blood glucose monitors that check your sugar 24 hours a day.

You’ll need to monitor your blood sugar levels throughout the day. If necessary, you may also need to take medication to manage cholesterol, high blood pressure, or other complications.

Treating type 2

Type 2 diabetes can be managed and sometimes even reversed with diet and exercise. It can also be treated with a variety of medications to help manage blood sugar.

The first-line medication is usually metformin (Glumetza, Glucophage, Fortamet, Riomet). This drug works by reducing glucose production in the liver. If metformin does not work, your doctor can prescribe another medication.

You’ll need to continuously monitor your blood sugar levels. You may also need medications to help manage blood pressure and cholesterol.

There’s no known prevention for type 1 diabetes.

You can lower your risk of type 2 diabetes if you:

  • manage your weight and focus on a nutrient-dense diet
  • exercise regularly
  • avoid smoking, high triglycerides, and low HDL cholesterol levels

If you have gestational diabetes or prediabetes, these habits can delay or prevent the onset of type 2 diabetes.

There’s no cure for type 1 diabetes. It requires lifelong disease management. But with consistent monitoring and adherence to treatment, you may be able to avoid more serious complications of the disease.

If you work closely with your doctor and make healthy lifestyle choices, type 2 diabetes can often be successfully managed or even reversed.

If you have gestational diabetes, it will likely resolve after your baby is born. However, you do have a higher risk of developing type 2 diabetes later in life.