Diabetes mellitus, or diabetes, is a disease that prevents your body from properly using the energy from the food you eat. People with diabetes have high blood glucose, also called high blood sugar or hyperglycemia.
Diabetes is a disorder of metabolism— the way the body uses digested food for energy. The digestive tract breaks down carbohydrates—sugars and starches found in many foods—into glucose, a form of sugar that enters the bloodstream. With the help of the hormone insulin, cells throughout the body absorb glucose and use it for energy.
Insulin is made in the pancreas, an organ located behind the stomach and below the liver. As blood glucose levels rise after a meal, the pancreas is triggered to release insulin. The pancreas contains clusters of cells called pancreatic islets. Beta cells within the pancreatic islets make insulin and release it into the blood.
Diabetes develops when the body doesn’t make enough insulin, is not able to use insulin effectively, or both. 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.
Insulin is made in the pancreas, an organ behind the stomach and below the liver.
The blood vessels and blood are the highways that transport sugar from where it is either taken in (the stomach) or manufactured (in the liver) to the cells where it is used (muscles) or where it is stored (fat). Sugar cannot go into the cells by itself. The pancreas releases insulin into the blood, which serves as the helper, or the "key," that lets sugar into the cells for use as energy.
When sugar leaves the bloodstream and enters the cells, the blood sugar level is lowered. Without insulin, or the "key," sugar cannot get into the body's cells for use as energy. This causes sugar to rise. Too much sugar in the blood is called "hyperglycemia" (high blood sugar) or diabetes.