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What symptoms can occur when insulin causes blood glucose to become too low?

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An anatomical illustration of the human pancreas shows its location near the stomach and intestines, a detailed cross-section highlighting ducts and the islet of Langerhans, and an inset of pancreatic tissue histology with labeled alpha, beta, and delta cells. — diabetes mellitus The islets of Langerhans are responsible for the endocrine function of the pancreas. Each islet contains beta, alpha, delta, and pancreatic polypeptide (PP) cells that are responsible for the secretion of pancreatic hormones. Beta cells secrete insulin, a well-characterized hormone that plays an important role in regulating glucose metabolism.

When insulin or other treatments for diabetes mellitus cause blood glucose levels to drop too low, a condition known as hypoglycemia occurs. The symptoms of this condition typically follow a characteristic pattern based on the severity of the glucose drop.1

Sympathoadrenal Symptoms

Mild hypoglycemia, often defined as blood glucose concentrations below 55 mg per 100 ml (3 mmol/l), triggers the activation of the sympathetic nervous system. This results in:
* Hunger
* Fatigue
* Tremor
* Rapid pulse
* Anxiety

Neuroglycopenic Symptoms

More severe hypoglycemia, typically below 45 mg per 100 ml (2.5 mmol/l), indicates glucose deprivation in the brain. These symptoms include:
* Blurred vision
* Impaired thinking and confusion
* Impaired consciousness
* Seizures
* Coma

These symptoms are nonspecific and should be attributed to hypoglycemia only when they are relieved by the administration of glucose.1