Diabetes is a disease that changes how your body processes food into energy.¹ How many types of diabetes are there? According to the Centers for Disease Control and Prevention (CDC), there are three main types — type 1 diabetes (T1D), type 2 diabetes (T2D), and gestational diabetes.²Other less common types include type 3c diabetes and latent autoimmune diabetes in adults (LADA).

Learning about the different types of diabetes and how they affect the body can help you better understand your condition and how it’s treated.

Type 1 Diabetes (T1D)

T1D is when your pancreas makes little to no insulin. Insulin is a hormone the pancreas makes to help your body’s cells use food for energy. Without insulin entering your cells, blood sugar levels continue to rise.

Doctors and researchers believe T1D is caused by an autoimmune condition that leads to your body’s immune system recognizing the beta cells (which make insulin) as foreign. The immune system attacks the cells so they can’t make insulin anymore.

Before a T1D diagnosis, you may have diabetic ketoacidosis (DKA), a condition caused by low insulin and extremely high blood sugar levels. Since your body can’t use blood sugar for energy, it starts using fats instead. The breakdown of fats releases ketones, which causes your blood to become acidic. This is a medical emergency that needs to be treated right away.³

Who Develops Type 1 Diabetes?

Originally, T1D was called juvenile diabetes because it tended to develop in children, teenagers, and young adults. However, doctors and researchers now know that T1D can develop at any age. T1D is much less common than T2D, affecting only 5% to 10% of people with diabetes.⁴

Genes involved in T1D may be passed down from parents to children, but people with those genes may not always go on to develop the disease. It’s also thought that certain triggers, such as infection with a virus, may trigger the immune system to attack the insulin-making cells of the pancreas. Unlike T2D, T1D is not caused by diet or lifestyle habits.

How Is Type 1 Diabetes Treated?

The main treatment for T1D is injected insulin. Insulin can’t be taken as a pill because stomach acid would break down the hormone. Many people use insulin pumps or give themselves shots before meals to help control their blood sugar levels. People with T1D need to regularly monitor their blood sugar levels and make sure they stay within a healthy range to prevent hypoglycemia, DKA, as well as long-term complications.⁴

Type 2 Diabetes (T2D)

T2D is a much more common form of diabetes, affecting around 10% of the United States’ population (more than 37 million people). T2D is caused by insulin resistance, which occurs when your cells can’t use insulin properly to allow blood sugar into your cells. To help compensate, your pancreas tries to make more insulin, but eventually your blood sugar rises to unmanageable levels.⁵

Who Develops Type 2 Diabetes?

Unlike T1D, T2D is mainly due to diet and lifestyle choices. Some people are more likely to develop T2D if they’re Hispanic or Latino, African American, Alaskan Native, or American Indian. Other risk factors include:⁶

Having a family member with T2D (brother, sister, or parent)
Being overweight
Not exercising at least three times a week
Previously having gestational diabetes
Having prediabetes

How Is Type 2 Diabetes Treated?

T2D can be treated with a combination of medication and diet and lifestyle changes. Diet recommendations for T2D focus on high-fiber foods, less carbohydrates, and eating on a regular schedule. Adults should also try to get at least 150 minutes of exercise per week, such as walking, running, or swimming.

Several different medication classes can treat T2D. In some cases, your doctor may prescribe insulin, mainly for cases where diet and lifestyle changes haven’t helped control your blood sugar levels.

Other types of medication include:⁷

Metformin is typically the first medication prescribed for treating T2D; it helps improve insulin sensitivity and reduce the amount of glucose (your body’s preferred form of sugar) made by the liver.
Sulfonylureas help the pancreas make more insulin.
Glinides help the pancreas make more insulin, and tend to work faster than sulfonylureas.
Glucagon-like peptide-1 (GLP-1) receptor agonists help lower blood sugar levels by helping the pancreas make more insulin and slowing passage of food from the stomach.¹²
Thiazolidinediones help improve insulin sensitivity by helping your body’s tissues use insulin.
Dipeptidyl peptidase-4 (DPP-4) inhibitors help reduce blood sugar levels, but not as effectively as other treatment options.
Sodium-glucose cotransporter-2 (SGLT2) inhibitors help lower your blood sugar levels by affecting the kidneys, causing extra glucose to be excreted in urine.

Gestational Diabetes

Gestational diabetes develops in pregnant women who weren’t diabetic previously. During pregnancy, your body makes many other hormones that can cause weight gain and make your cells less sensitive to insulin. As a result, blood sugar levels rise, causing a temporary form of diabetes. Gestational diabetes typically develops near the 24th week of pregnancy (in the second trimester), so your doctor will likely test you around then.⁸

Who Develops Gestational Diabetes?

Gestational diabetes affects anywhere between 2% to 10% of pregnancies in the United States. Women are at a higher risk of developing gestational diabetes if they:⁶

Are 25 years or older
Are overweight
Have had gestational diabetes before in another pregnancy
Have a family member with T2D
Have given birth to a baby who weighed nine pounds or more
Are Hispanic or Latino, Alaska Native, Native Hawaiian, African American, or Pacific Islander
Have polycystic ovarian syndrome (PCOS)

Of the women who develop gestational diabetes, around 50% will go on to develop T2D. Your doctor will continue to monitor your blood sugar levels after you have your baby to determine your risk.⁸

How Is Gestational Diabetes Treated?

You can manage gestational diabetes by eating a healthy diet and exercising safely during pregnancy. Your doctor may have a registered dietician help you make a meal plan that focuses on lean proteins, complex carbohydrates, and fruits and vegetables. You’ll also have an exercise plan to help increase insulin sensitivity and lower blood sugar levels. If needed, your doctor may prescribe insulin injections or metformin.⁸

Less Common Types of Diabetes

While T1D, T2D, and gestational diabetes are all fairly common, there are other types of diabetes many people haven’t heard of. These include type 3c diabetes (also known as secondary diabetes), and latent autoimmune diabetes in adults (LADA).

Type 3c Diabetes (Secondary Diabetes)

Type 3c diabetes develops when the pancreas stops producing insulin as the result of an injury or illness. You may develop type 3c diabetes if you’ve had pancreatic cancer, pancreatitis (inflamed pancreas), cystic fibrosis, or hemochromatosis (too much iron in the body). It can also develop if you have your pancreas removed. This means your body isn’t getting enough insulin, so your blood sugar levels begin to rise.

Around 9% of people with diabetes have type 3c, but the condition often goes undiagnosed. Your doctor may see signs of pancreatic damage on imaging scans, or you may notice symptoms such as losing weight unexpectedly, feeling more tired than usual, and having stomach pain. Type 3c diabetes can be treated with insulin shots and medications used to treat T2D.^9,10

Latent Autoimmune Diabetes in Adults (LADA)

Latent autoimmune diabetes in adults (LADA), sometimes known as type 1.5 diabetes, is an autoimmune form of the disease. LADA is similar to T1D in that the pancreas eventually stops making insulin because beta cells become damaged. However, LADA progresses slowly over years, so you won’t need insulin for several months to years after diagnosis.

Most people who develop LADA are 30 or older, and they’re typically diagnosed with T2D first. Many people who are misdiagnosed will make lifestyle changes that don’t affect their blood sugar levels. As the condition progresses, you’ll eventually need insulin injections. Doctors and researchers are continuing to learn new and better ways to treat LADA.¹¹