Glucagon is a hormone that raises glucose (blood sugar) levels. It is available as a prescription medication that can be injected to treat severe insulin-induced hypoglycemia or insulin shock.

Glucagon acts in the opposite manner of insulin, which lowers blood glucose by moving it into the body’s cells. Glucagon and insulin are both naturally occurring messenger chemicals normally produced by the pancreas that are necessary to regulate glucose, the body’s main source of energy. 

Depending on the amount of insulin in the blood, glucose levels may rise or fall. Without insulin, glucose levels in the blood will rise, leading to hyperglycemia. When too much insulin is present in the blood, symptoms of low glucose can occur. These symptoms may include:

• Shakiness
• Disorientation
• Rapid heartbeat (palpitations)
• Sweating
• Nervousness
• Dizziness
• Seizures
• Fainting

Left untreated, severe hypoglycemia can cause brain damage, coma, heart attack, stroke or even death. Diabetes patients should learn to recognize the early symptoms of low glucose so they can follow the steps recommended by their physician.

Glucagon is not recommended for treating hypoglycemia that is chronic or is due to alcohol consumption, starvation or adrenal insufficiency. The U.S. Food and Drug Administration suggests treating these cases with glucose.

Physicians may advise diabetic patients, especially those with type 1 diabetes or unstable diabetes, to carry glucagon kits. These kits contain emergency doses of glucagon and syringes.

Glucagon also has other medical uses, such as improving results of x-ray tests and treating an overdose of blood pressure medication.