Glucose is a type of sugar. It is your body's main source of energy. Hypoglycemia is a condition where the level of glucose in your blood becomes low enough to cause symptoms. When blood glucose drops too low, your body does not have enough energy to function properly.

Medications for diabetes are the most common cause, particularly when combined with the following factors:

  • Taking too much blood sugar-lowering medication
  • Delaying or missing meals, or eating too little at meals
  • Too much or too strenuous exercise

Reactive hypoglycemia may also occur in people without diabetes. It is now thought to be quite rare.

Other causes of hypoglycemia include:

  • Alcohol abuse, especially binge drinking coupled with not eating
  • Starvation
  • Early pregnancy
  • Certain pituitary or adrenal gland conditions
  • Certain liver conditions
  • Kidney disease
  • Certain types of stomach surgery
  • Tumor that makes insulin
  • Hereditary enzyme or hormone deficiencies
  • Severe illness or infection