What Is the Cause of High Serum Glucose Levels on a Blood Test?

Serum glucose, or blood glucose, is a measurement of the glucose levels in the bloodstream at any given time. High blood glucose readings have a number of potential underlying causes.

The Facts

EndocrineWeb notes methods for testing blood glucose that include the fasting blood glucose test—which measures glucose levels after 10 to 16 hours without food or drink—and the oral glucose tolerance test, which follows a fasting glucose procedure with a measured response to the ingestion of a high-sugar liquid.

Causes

The U.S. National Library cites potential causes of high test readings that include diabetes, pre-diabetes, overactive thyroid (hyperthyroidism), pancreatitis (pancreas infection or inflammation), pancreatic cancer and a rare adrenal tumor called pheochromocytoma.

Stress-Related Elevation

A number of conditions can temporarily elevate blood glucose readings through significant body stress, notes the U.S. National Library of Medicine. These include surgery, physical injury, heart attacks and strokes.

Medications

The U.S. National Library of medicine also notes a number of medications that can elevate blood glucose readings. These include diuretics, corticosteroids, certain antipsychotics, epinephrine, tricyclic antidepressants, phenytoin and lithium.

Gestational Diabetes

EndocrineWeb notes that pregnancy can trigger a temporary condition called gestational diabetes, with symptoms including high blood glucose.

References

• University of Michigan Health System - C.S. Mott Children's Hospital: Blood (Serum) Glucose Test
• EndocrineWeb: Diagnosing Diabetes
• U.S. National Library of Medicine - National Institutes of Health: Glucose Test - Blood

Resources

• Lab Tests Online: Glucose - The Test