We hear a lot about diabetes, but you may wonder what exactly it is. Diabetes mellitus (its full name) is a chronic disease caused by dysregulation of the endocrine system. Diabetes affects how our bodies turn food into energy. There are three main types of the condition: type 1, type 2 and gestational.

To understand diabetes, we first need to understand what insulin is and how it works. Insulin is a hormone the pancreas makes and secretes in response to glucose (blood sugar). Various organs throughout our body normally respond to insulin by taking in glucose and storing it for later use. With diabetes, either the body isn’t making insulin or the organs are not responding to it.

Now, let’s talk about the three types.

Type 1 diabetes

In people with type 1 diabetes, the pancreas produces little to no insulin. Typically (but not always), signs of type 1 appear in childhood or the teen years. This used to be called juvenile diabetes. Researchers are still figuring out how and why type 1 diabetes develops in some people, but we know it is a genetic disorder in which the immune system attacks and destroys the insulin-producing cells in the pancreas.

This destruction starts early and builds over time until the levels of insulin are so low that high blood sugar levels make people sick. People with undiagnosed type 1 diabetes often end up in the hospital due to diabetic ketoacidosis, a condition in which their blood sugar is super high and their body cannot convert it into energy. Type 1 diabetes requires lifelong treatment with synthetic insulin, careful diet and constant blood sugar monitoring.

Type 2 diabetes

In type 2 diabetes, the body is able to make insulin, but the organs do not respond to it, which leads to a buildup of glucose in the blood. Like with type 1 diabetes, constant high blood sugar can cause organ damage over time. Type 2 diabetes may develop as a result of lifestyle choices, such as an unhealthy diet, inactivity, smoking and obesity. The treatment for type 2 diabetes is more focused on lifestyle changes—eating healthier and exercising more—before moving to long-term medications.

Gestational diabetes

Gestational diabetes develops during pregnancy. Interestingly, people often do not show any symptoms, which is why routine blood sugar tests are performed during pregnancy. Hormonal changes during pregnancy can contribute to difficulties processing blood sugar efficiently. Researchers are still trying to understand why some people develop gestational diabetes, but we know obesity, lack of physical activity, race and polycystic ovary syndrome are risk factors. Gestational diabetes usually resolves on its own after delivery, but people who develop it have a greater risk of developing type 2 diabetes.

Regardless of the type, diabetes is not something to overlook. Minimize your risk by staying active and following a healthy diet. If your family has a history of diabetes ask your doctor to check your blood sugar.