Diabetes mellitus is a condition in which your blood sugar levels are too high because the body cannot control the level properly. Insulin is a hormone that is produced by the pancreas and lowers blood sugar by helping the sugar (glucose) to move into your body cells which use it as a source of energy.
There are different types of diabetes: Type I diabetes occurs when your pancreas does not make any insulin and may be diagnosed in childhood or early teens. Type 2 diabetes occurs when your pancreas is unable to make enough insulin or it no longer works effectively to reduce blood sugar levels. High levels of blood sugar can cause serious problems which may damage your eyes, kidneys and nerves. You may also be at higher risk of having a heart attack or stroke or it may be fatal if the blood sugar levels become too high and you do not receive the correct treatment.