What can cause hypoglycemia?

Hypoglycemia (hypoglycæmia in the UK) is a medical term referring to a pathologic state produced by a lower than normal amount of sugar (glucose) in the blood. The term hypoglycemia literally means "under-sweet blood" (Gr.hypo-, glykys, haima). Hypoglycemia can produce a variety of symptoms and effects but the principal problems arise from an inadequate supply of glucose as fuel to the brain, resulting in impairment of function (neuroglycopenia). Derangements of function can range from vaguely "feeling bad" to coma, and (rarely) permanent brain damage or death. Hypoglycemia can arise from many causes and can occur at any age. The most common forms of moderate and severe hypoglycemia occur as a complication of treatment of diabetes mellitus with insulin or oral medications.