What is Diabetes?

Diabetes mellitus is a group of chronic metabolic diseases characterized by high levels of blood glucose (blood sugar). In a person with diabetes, the normal use of food for energy is disrupted because of defects in insulin production, insulin action, or both. Insulin is a hormone which assists with the uptake of glucose into the body’s cells. When insulin defects are present, the normal pathway of energy production is disrupted and high blood glucose levels result.

There are three main types of diabetes:

Type 1 diabetes

Type 1 diabetes results from the failure of the insulin-producing cells of the pancreas to produce insulin. People with type 1 diabetes must take daily injections of insulin. It is thought to be an autoimmune disorder, and it occurs most frequently in children and young adults. Its onset is sudden and diagnosis is rapid after the start of symptoms. Only about 5% to 10% of people with diabetes have type 1. Type 1 diabetes was formerly called insulin-dependent diabetes mellitus or juvenile-onset diabetes.

Type 2 diabetes

Type 2 diabetes is the most prevalent form of the disease, occurring in about 90% to 95% of people with diabetes. In this form of diabetes, the body either does not produce enough insulin or it cannot use it properly. A person with type 2 diabetes can experience symptoms very gradually, often over years, thus delaying diagnosis and proper management. Management and control of diabetes is critical to preventing the development of complications such as cardiovascular disease, eye disease, or kidney disease. Type 2 was formerly referred to as non-insulin-dependent diabetes mellitus or adult-onset diabetes.

Gestational diabetes

Gestational diabetes occurs only during pregnancy, often in women with no prior history of the disease. Gestational diabetes requires strict management, including insulin use to stabilize blood sugar levels to help prevent complications with the baby. Women with gestational diabetes are at a higher risk of developing type 2 diabetes later in life and of having future pregnancies with gestational diabetes.


Pre-diabetes is a term used to distinguish people who are at increased risk of developing diabetes. People with pre-diabetes have blood sugar levels which are higher than normal but not yet high enough to warrant a diagnosis of diabetes. The Centers for Disease Control and Prevention (CDC) estimate that roughly 79 million adults have pre-diabetes nationwide.