What causes low blood sugar (hypoglycemia)?

Low blood sugar can occur through several mechanisms. The most frequent causes are medication-related, meal-related (skipping or insufficient intake), alcohol, heavy exercise, and hormonal or metabolic imbalances. A medical evaluation is needed to determine the exact cause.

The following are common and less common contributors to hypoglycemia. This is not an exhaustive list — your personal medical history matters.

• Diabetes-related hypoglycemia due to insulin or oral antidiabetic drugs used at the wrong dose or timing
• Missed meals, inadequate food intake, or irregular meal schedules
• Hypoglycemia due to alcohol or nutritional deficiencies
• Increased glucose use after prolonged or intense exercise
• Adrenal insufficiency or other hormonal/metabolic causes

The appropriate specialty depends on your medical history and the severity of symptoms. The list below is a general guide.

• Endocrinology and Metabolic Diseases: Suitable for recurring or unexplained low blood sugar, diabetes-related problems, or when hormonal evaluation is needed.
• Family Medicine or Internal Medicine: Good first step for initial assessment, medication review and direction to specialists.
• Emergency Medicine: Go to the emergency department for severe signs such as loss of consciousness, seizures, severe breathing or circulation problems, or rapidly worsening confusion.

To speed up evaluation bring or note the information below.

• A list of all medications and supplements you take (including doses and how often)
• Timing, duration and frequency of symptoms and any possible triggers
• Time of last meals or snacks, alcohol use and exercise habits
• Any available blood glucose readings or previous medical records

The following require immediate assessment—go to the emergency department without delay if they occur.

• Loss of consciousness or rapidly worsening confusion
• Seizures (convulsions)
• Severe breathing or circulation problems, extreme dizziness or inability to maintain balance