An insulin overdose is a serious medical emergency caused by excess insulin driving blood sugar levels dangerously low (severe hypoglycemia). This excess insulin rapidly causes cells to absorb glucose, starving the brain and vital organs of energy. Immediate intervention prevents life-threatening complications like seizures, coma, or permanent neurological damage. Severity depends on the amount and type of insulin taken, as long-acting insulins can cause hypoglycemia lasting for days.
Recognizing the Signs of Severe Hypoglycemia
Symptoms of an insulin overdose relate directly to the brain’s lack of glucose and can progress quickly. Early signs of low blood sugar (below 70 mg/dL) involve the body’s adrenaline response, including feeling shaky, anxious, dizzy, intense hunger, rapid heartbeat, or cold sweats.
As blood sugar continues to fall, the brain suffers glucose deprivation, leading to neuroglycopenic symptoms. These severe signs involve cognitive and motor dysfunction, such as confusion, slurred speech, or difficulty coordinating movements. If not corrected, the individual may experience seizures, become disoriented, or lose consciousness.
Immediate At-Home Steps for Conscious Individuals
For individuals who are awake, alert, and able to swallow safely, immediate treatment involves consuming fast-acting carbohydrates to raise blood glucose quickly. This standard approach is known as the “Rule of 15,” which dictates consuming 15 grams of rapidly absorbed carbohydrates.
Suitable sources include three to four glucose tablets, four ounces of fruit juice or regular soda, or one tablespoon of honey or granulated sugar. Avoid high-fat foods like chocolate or cookies, as fat slows glucose absorption. After consumption, wait 15 minutes and recheck the blood sugar level.
If blood glucose remains below 70 mg/dL after 15 minutes, repeat the 15-gram carbohydrate intake and waiting period. This cycle continues until the blood sugar is back in a safe range. Once stable, eat a small snack containing protein and a longer-acting carbohydrate, such as crackers and cheese, to prevent the sugar from dropping again.
Emergency Protocol for Unconscious Individuals
If the person is unconscious, having a seizure, or unable to swallow, treatment must shift from oral sugar to emergency glucagon administration. Glucagon is a hormone that signals the liver to release stored glucose (glycogen) into the bloodstream, counteracting insulin’s effects. A caregiver must administer glucagon, available as an injectable kit or nasal spray, before calling emergency services.
Follow the product’s packaging instructions precisely for administration. After giving the medication, immediately turn the person onto their side. This is a safety measure because glucagon often causes nausea and vomiting, and positioning prevents the risk of choking or aspiration.
Emergency services should be called right after administration. Glucagon typically causes consciousness to return within 15 minutes. If the person does not wake up, a second dose may be given while waiting for medical help. Even if they wake up, they must be given a fast-acting sugar source and a snack once they can safely swallow, and medical personnel must still be consulted.
Professional Medical Intervention and Monitoring
Professional treatment for severe insulin overdose centers on providing intravenous (IV) glucose, or dextrose. A rapid bolus of concentrated dextrose (e.g., 50% solution) is typically given immediately to quickly raise blood glucose to a safe range.
Following the initial bolus, a continuous infusion of a weaker dextrose solution (e.g., 10% dextrose) is started to maintain stable levels. Blood glucose is monitored frequently, often every 15 minutes, because high insulin doses can continue to drive sugar down for an extended period, especially with long-acting insulin. Patients may require IV glucose for many hours or days due to the prolonged action of large insulin doses.
Even after stabilization and stopping IV dextrose, the patient must remain under medical observation for a prolonged period, sometimes 12 hours or more. This extended monitoring prevents rebound hypoglycemia, which occurs when blood sugar drops again while excess insulin remains active. Medical staff also monitor for and correct electrolyte imbalances, such as low potassium.