In diabetes, the pancreas does not make enough insulin. The blood sugar remains high because insulin is not available to transport sugar from blood into the cells of the body. Diabetes is diagnosed when blood sugar levels are higher than normal, which is known as hyperglycemia (hyper = high; glycemia = blood sugar).

To treat this disease, diabetics take medication. Type 1 diabetics lack insulin completely and so they need insulin injections. Type 2 diabetes produce insufficient amounts of insulin, and take pills (called oral hypoglycemic agents) to regulate their blood sugar.

Too-high doses of insulin or oral hypoglycemic pills can cause hypoglycemia in diabetics. The treatment is to eat or drink something containing sugar right away.