Hypoglycemia and Headaches

Mid adult woman with headache
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When we think of how sugar impacts our health, it's often because we’re watching our waistline or are worried about cavities. However, the levels of sugar in our bodies can also affect our headaches.

Understanding Hypoglycemia

To better understand how sugar triggers headaches, let’s first talk about hypoglycemia. Hypoglycemia occurs when the body’s glucose (or sugar) levels drop below 70 mg/dL. This can not only trigger a headache, but also cause confusion, dizziness, shakiness, hunger, irritability, and weakness.

If your glucose levels are not brought back up to a level between 70 to 100 mg/dL quickly, then symptoms can worsen to include numbness, poor concentration, poor coordination, passing out, and even coma.

There are a few causes of hypoglycemia. One cause is fasting, as the body is not able to take in enough glucose to maintain proper levels.

Hypoglycemia is also common in people with diabetes and may occur when someone takes too much insulin or diabetes medicine, takes the medicine at a different time than usual, waits too long to eat or doesn’t eat enough, exercises at a different time of day, or drinks alcohol.

Hypoglycemia can also occur without diabetes. It can stem from excessive alcohol consumption, chronic illnesses like kidney disease, overproduction of insulin by the pancreas, or other endocrine-related issues.

Headaches From Hypoglycemia

Headaches from hypoglycemia are usually described as a dull, throbbing feeling in the temples. The pain can occur with other hypoglycemic symptoms, like blurry vision, increased heart rate, nervousness, fatigue, irritability, and confusion.

Hypoglycemia can also trigger a migraine headache. In fact, some migraine sufferers report craving carbohydrates before the migraine hits, which may be the body’s way of regulating blood sugar and preventing the headache.

Interestingly, migraine headaches caused by hypoglycemia may not be accompanied by typical migraine symptoms like nausea, vomiting, and sensitivity to light and sound. Instead, the migraine is more likely to be accompanied by the hypoglycemia symptoms noted above. Although, this is not a hard and fast rule.

Preventing Hypoglycemia-Induced Headaches

To prevent your hypoglycemia-induced headache, it’s best to prevent your blood sugars from dropping.

If you have diabetes, it's important to follow the medical management plan established by your doctor. Be sure to check in regularly with your doctor so he or she can monitor you for any changes that may affect your treatment plan.

If your hypoglycemia is not caused by diabetes, then it's important to change your diet to prevent low blood sugar. Doctors generally suggest that people who suffer from hypoglycemia eat smaller, more frequent meals and snacks throughout the day. In addition, it's advised to go no more than three hours between eating meals.

A well-balanced diet rich in protein and fiber will also help to maintain your blood sugar levels. Lastly, foods that contain sugar and alcohol should be limited, especially on an empty stomach. Regular physical activity is another important management technique.

Treating a Hypoglycemia-Induced Headache

It's important for people with hypoglycemia to have their blood sugar monitor and a snack with them at all times. If your blood sugar dips, it's important to get your glucose level back up between 70 mg/dL and 100 mg/dL, as quickly as possible.

If you are hypoglycemic, follow the 15/15 rule to feel better fast:

  1. If your blood glucose is low, or if you can't test but feel like it is, consume 15 grams of carbohydrate. You can use over-the-counter glucose tablets or gel, drink a 1/2 cup of juice or non-diet soda, or eat 5 lifesavers or 3 peppermint candies. It is important that you choose a food that is nearly pure carbohydrate. The protein in peanut butter crackers, for example, will slow the quick absorption of carbohydrate that you need when hypoglycemic.
  2. Wait 15 minutes. If you're still low, repeat step 1.
  3. If you're still low, call 911.
  4. If your glucose has improved, eat a small snack. This is when those peanut butter cheese crackers will come in handy.

If you are concerned about your symptoms or the headaches don't subside with one of the quick fixes above, consult with your doctor and get a ride to the hospital. It is very important not to drive yourself when having a hypoglycemic episode. If there is no one who can drive you, then call 911.

Sometimes, hypoglycemia will cause a person to pass out or lose consciousness. Be sure to not try to feed an unconscious person with hypoglycemia, as this can cause choking. Keep your friends and family informed about ways they can act quickly to help you with a hypoglycemic episode.

A Word From Verywell

If you have diabetes and are experiencing episodes of hypoglycemia, it's essential to see your doctor. Hypoglycemia is serious and can be life-threatening. Your doctor can evaluate the cause of your hypoglycemia and alter your treatment plan accordingly.

If you do not have diabetes, but suspect hypoglycemia may be a cause of your headaches, see a doctor for a proper diagnosis. If this is the case, changing your lifestyle and nutrition habits should treat your headaches.

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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Diabetes Association. Hypoglycemia (low blood glucose). 1995-2019.

  2. National Institute of Diabetes and Digestive and Kidney Diseases. Low blood glucose (hypoglycemia). Updated August 2016.

  3. National Headache Foundation. Hypoglycemia.

  4. University of Wisconsin Hospitals and Clinics Authority. Nutrition management of low blood sugar without diabetes (postprandial syndrome and reactive hypoglycemia. 2019.

  5. Cleveland Clinic. Hypoglycemia (low blood sugar). 2019.

Additional Reading
  • Candan FU. EHMTI-0229. A case of migraine like headache with postprandial hypoglycemia treated with lifestyle. J Headache Pan. 2014;15(Suppl 1):G39.
  • Headache Classification Committee of the International Headache Society. "The International Classification of Headache Disorders: 3rd Edition (beta version)". Cephalalgia 2013;33(9):629-808.
  • Torelli P, Evangelista A, Bini A, Castellini P, Lambru G, Manzoni GC. Fasting headache: a review of the literature and new hypotheses. Headache. 2009 May;49(5):744-52.
  • Torelli P, Manzoni GC. Fasting headache. Curr Pain Headache Rep. 2010 Aug;14(4):284-91.