Diabetes mellitus (commonly referred to as diabetes) is considered a complex group of diseases with a variety of causes. It is a chronic disorder of metabolism and is characterized by elevated blood glucose levels or hyperglycemia.
After carbohydrates (sugars and starches found in many foods) are ingested, the body breaks down the ingested carbohydrates into glucose which enters the bloodstream and, with the help of the hormone insulin, enters cells throughout the body. Insulin is produced and secreted by the pancreas. Within the pancreas, clusters of cells called islets contain beta cells, which manufacture insulin and release it into the blood. As the blood glucose level rises after a meal, the pancreas is triggered to release insulin. When an individual has diabetes, the pancreas either does not produce adequate insulin, the body incorrectly uses the insulin that is produced, or both.
Insulin secreted into the bloodstream by the pancreas helps glucose enter the body’s cells to be used for energy production. A lack of insulin or improperly functioning insulin causes glucose not to enter the cells, causing blood glucose levels to rise, producing hyperglycemia. As a result, glucose builds up in the blood instead of being absorbed by cells in the body. The body’s cells are then starved of energy despite high blood glucose levels.
Over time, hyperglycemia can damage nerves and blood vessels, leading to complications such as heart disease, stroke, kidney disease, blindness, dental disease, and amputations. Other complications of diabetes may include increased susceptibility to other diseases, loss of mobility with aging, depression, and problems with pregnancy.