Diabetes is a common group of chronic metabolic diseases in which defects in insulin production and/or function cause high blood sugar (glucose) levels in the body. Insulin is a hormone released by the pancreas when we eat food; it allows sugar to go from the blood into the cells. If the cells of the body are not using insulin well, or if the body is unable to make any or enough insulin, sugar builds up in the blood.
Symptoms include excessive thirst, hunger, and urination; fatigue; slow-healing sores or cuts; and blurry vision. Long-term complications of diabetes can include kidney failure, nerve damage, and blindness.