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Health Information Center


  • Rick Alan
Publication Type:



(Low Blood Glucose; Low Blood Sugar)


Hypoglycemia is a low level of glucose in the blood. Glucose is your body's main source of energy. Low levels make it hard for your body to work as it should. This will cause a wide range of problems.


Diabetes medicine is a common cause of hypoglycemia. Other medicine may also cause problems with blood glucose but it is rare unless there is kidney failure.

Hypoglycemia can also happen in people without diabetes. This is less common. It may be caused by:

  • Alcohol use disorder, especially with heavy drinking and not eating
  • Starvation
  • Early pregnancy
  • Hormone imbalances from some pituitary or adrenal gland problems
  • Certain liver problems
  • Kidney disease
  • Certain types of stomach surgery
  • Tumor that makes insulin
  • Severe illness or infection

Risk Factors

Things that may increase the chance of hypoglycemia while taking diabetes medicine are:

  • Taking too much medicine
  • Eating too little at meals, delaying or missing meals
  • Unplanned intense exercise
  • Sickness like cold or flu


Symptoms may start slowly or quickly. Hypoglycemia may cause:

  • Sweating
  • Nervousness
  • Lightheadedness
  • Rapid heartbeat
  • Hunger
  • Headache
  • Tingling feeling around the mouth

As hypoglycemia worsens, it may cause:

  • Fatigue
  • Weakness
  • A change in behavior or confusion
  • Poor control of movements
  • Seizure
  • Loss of consciousness

Sensitivity to low blood glucose may change over time. Early symptoms may start to fade if you have a lot of events. This will make it harder to feel when glucose starts to fall.


The doctor may suspect hypoglycemia based on your health and symptoms. Glucose levels can be measured with a quick blood test. A device pricks a finger to draw a drop of blood. A machine will measure the glucose in the blood drop.

Other tests may need to be done if you do not have diabetes. This may include checking your blood glucose levels after fasting.


Treatment will bring blood glucose levels back to normal. Other steps may be needed to keep it from happening again. Quick care can stop further health problems.


Following treatment plan may help prevent some hypoglycemia.





  • Hypoglycemia (low blood glucose). American Diabetes Association website. Available at: https://www.diabetes.org/diabetes/medication-management/blood-glucose-testing-and-control/hypoglycemia. Accessed February 12, 2021.
  • Hypoglycemia in diabetes. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/hypoglycemia-in-diabetes/. Accessed February 12, 2021.
  • Hypoglycemia in persons without diabetes. EBSCO DynaMed website. Available at: https://www.dynamed.com/approach-to/hypoglycemia-in-adults-approach-to-the-patient-without-diabetes. Accessed February 12, 2021.
  • Low blood glucose (hypoglycemia). National Institute of Diabetes and Digestive and Kidney Diseases website. Available at:https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-problems/low-blood-glucose-hypoglycemia. Accessed February 12, 2021.


  • Marcin Chwistek, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.