Glucagon Blood Test

Why this test may be ordered

• To help diagnose hypoglycemia (low blood glucose).
• To evaluate symptoms of a pancreatic tumor, such as rash, diarrhea, or weight loss.
• To monitor people with diabetes in some cases.

Preparation and collection

You may need to fast (not eat or drink) for several hours before the test.

A health care professional will take a blood sample from a vein in your arm, using a small needle. This usually takes less than five minutes.

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

Understanding results

This test measures the amount of glucagon in your blood. Glucagon works with insulin to help control your blood glucose (sugar) level.

• Glucagon level within the normal range: Your glucagon level is within the normal range. Limitation: A single normal result does not rule out all conditions. Your healthcare provider will consider your symptoms and medical history. Next step: Your healthcare provider will interpret your result along with other information.
• Glucagon level outside the normal range: This may be a sign of hypoglycemia, diabetes, acute or chronic pancreatitis, or a rare pancreatic tumor (glucagonoma). Limitation: An abnormal result does not diagnose a specific condition. Additional testing is needed to identify the cause. Next step: Your healthcare provider may order imaging or other lab tests to determine the cause.

• The test does not diagnose a specific condition; results must be interpreted by a healthcare professional.
• Fasting may be required before the test.

What to do next

If your glucagon level is outside the normal range, your healthcare provider may recommend additional tests to determine the cause.

• What do my glucagon test results mean for my health?
• Do I need any follow-up tests?
• What symptoms should I watch for?

Evidence source

U.S. National Library of Medicine: Glucagon Blood Test