Hyperglycemia is the condition of having an excessive amount of glucose circulating in the blood plasma. Etymology hyper- in Greek meaning "too much"; -glyc- in Greek meaning "sweet"; -emia meaning "of blood".

It is the basic and most consistent finding in all types of diabetes mellitus.

In fasting adults blood plasma glucose should not exceed 100 mg% (normal blood glucose levels when fasting are below 126 mg/dl and above 60 or 70 depending on the individual patient). Sustained higher levels of blood sugar cause damage to the blood vessels and to the organs they supply, leading to the complications of diabetes.

The opposite of hyperglycemia is hypoglycemia.

See also

• diabetic coma
• Category:Metabolic disorders