More than 37 million U.S. adults are living with diabetes, according to the Centers for Disease Control and Prevention. One in five of those adults aren’t aware they have it.

Diabetes is a chronic condition that affects the way your body uses and breaks down blood glucose (sugar). People with diabetes either don’t produce enough insulin or are unable to use insulin well to break down sugar in their blood. This can lead to serious health issues.  

It’s important to know the difference between the three main types of diabetes and how they affect your body. Even though symptoms of diabetes can be similar, treatments differ between each type. The three main types of diabetes include Type 1, Type 2 and gestational diabetes, according to the CDC.

What is Type 1 diabetes?

Type 1 diabetes occurs when the body can’t produce enough insulin. It’s believed that an autoimmune reaction causes your body to stop making it, according to the CDC. Know this. With Type 1 diabetes, the onset of symptoms can occur quickly. Type 1 diabetes is usually diagnosed in children, teens and young adults. People with Type 1 diabetes need to take insulin every day to manage their diabetes.

What is Type 2 diabetes?

Type 2 diabetes occurs when your body doesn’t use the insulin it produces efficiently. This causes high blood sugar levels in your body. Many more people are diagnosed with Type 2 diabetes compared to Type 1 diabetes.

With Type 2 diabetes, the onset of symptoms occurs gradually over time. Symptoms often go unnoticed. That’s why it’s important to get tested if you’re at risk. You can prevent or delay the onset of Type 2 diabetes by maintaining a healthy weight, being active and eating a healthy diet, according to the CDC.

What is gestational diabetes?

Sometimes, gestational diabetes develops in pregnant women who have never had diabetes. Developing gestational diabetes during pregnancy can put your baby at higher risk for health problems. Gestational diabetes usually goes away after your baby is born, but can increases your risk for Type 2 diabetes later in life. It also increases the likelihood of your baby developing obesity as a child or teen and developing Type 2 diabetes later in life.

What about prediabetes?

Prediabetes means your blood sugar levels are elevated and you’re at risk for developing Type 2 diabetes. The good news is you can take steps to reverse it, according to the CDC.

Participants in a CDC Lifestyle Change Program who lost 5 to 7% of their body weight and added 150 minutes of exercise per week cut their risk of developing Type 2 diabetes more than 50%, according to the CDC. Lifestyle changes included a healthy diet, getting regular exercise, and learning how to manage stress.