Diabetes mellitus (or more commonly, simply, diabetes) involves high blood glucose (hyperglycemia or high blood sugar) that is not properly regulated naturally by the body. Normal blood glucose is between 70 and 140 mg/dL (milligrams per deciliter), and strong deviations above or below this range can cause both acute and chronic health problems. Common symptoms of hyperglycemia include excessive thirst and/or hunger and frequent urination, whereas symptoms of hypoglycemia (low blood glucose) include shakiness, headache, hunger, and sweating. Both hyper- and hypoglycemia can result in altered mental states and, if severe, unconsciousness and death as well.

The term diabetes mellitus comes from Greek and Latin: diabetes comes from Greek and relates to excessive urinary output, and mellitus comes from Latin, relating to sweetness in the urine. ...