There are three main types of diabetes: type 1 diabetes, type 2 diabetes, and gestational diabetes.

1. Type 1 diabetes: This type of diabetes, also called insulin-dependent diabetes or juvenile diabetes, is an autoimmune disease in which the immune system attacks and destroys the insulin-producing cells in the pancreas. As a result, the body is unable to produce insulin, which is necessary to regulate blood sugar levels. Type 1 diabetes is usually diagnosed in children and young adults, though it can occur at any age.

2. Type 2 diabetes: This type of diabetes, also called non-insulin-dependent diabetes, is a metabolic disorder in which the body becomes resistant to insulin, and the pancreas may not produce enough insulin to maintain normal blood sugar levels. Type 2 diabetes is often associated with obesity, physical inactivity, and poor diet, and it is more common in adults, especially those over 40 years of age.

3. Gestational diabetes: This type of diabetes occurs during pregnancy and usually goes away after the baby is born. Gestational diabetes can develop when the hormones produced during pregnancy interfere with the body's ability to use insulin effectively. Women who have had gestational diabetes are at increased risk of developing type 2 diabetes later in life.

Less common types of diabetes include monogenic diabetes, which is caused by a mutation in a single gene, and cystic fibrosis-related diabetes, which is a form of diabetes that is associated with cystic fibrosis.

Regardless of the type of diabetes, the goal of treatment is to maintain normal blood sugar levels to prevent complications such as nerve damage, kidney damage, and cardiovascular disease. Treatment may involve lifestyle changes, such as diet and exercise, as well as medications and insulin therapy.