Headache From Low Blood Sugar

Why hypoglycemic headaches occur

Hypoglycemia (low blood sugar) can cause and worsen headaches. A hypoglycemic headache can feel like dull throbbing in the temples. If you get migraines, low blood sugar may trigger a migraine episode.

This article discusses why low blood sugar can cause headaches and migraines, as well as how you can prevent and treat them.

A woman with an extreme headache
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Why Does Low Blood Sugar Cause Headaches?

You may get a headache when you body's glucose (or sugar) levels drop below 70 mg/dL—the benchmark for hypoglycemia.

Headaches from blood sugar this low 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.

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.

Migraine Headaches

Hypoglycemia can also trigger a migraine headache. In fact, some people who get migraines report craving carbohydrates before the migraine hits, which may be the body’s way of regulating blood sugar and attempting to prevent the headache.

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.

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.

Preventing Hypoglycemia-Induced Headaches

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

Manage Your Diabetes

If you have diabetes, it's important to follow the medical management plan established by your healthcare provider.

Be sure to check in regularly with your healthcare provider so they can monitor you for any changes that may affect your treatment plan.

Lifestyle and Diet Changes

Hypoglycemia-induced headaches can occur when you are fasting. This is because your body isn't able to maintain its glucose levels if you're not eating anything.

Healthcare providers generally suggest that people who have 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 maintain your blood sugar levels. Excessive alcohol and sugar consumption can cause hypoglycemia, so sugar and alcohol should be limited, especially on an empty stomach.

Regular physical activity is another important management technique.

Manage Chronic Illness

Some other causes of hypoglycemia include chronic illnesses like kidney disease, overproduction of insulin by the pancreas, or other endocrine-related issues.

If you have any of these conditions, it's important to talk to your healthcare provider about treatment options that may help improve your condition and prevent hypoglycemic headaches.

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, you need to get your glucose level back up between 70 mg/dL and 100 mg/dL as quickly as possible.

If you are hypoglycemic, or think you might be, follow the 15/15 rule to feel better fast: Consume 15 grams of carbohydrates and then wait 15 minutes. Then:

  • If your glucose has increased/you start to feel better, eat a small snack.
  • If you're still low or feel low, repeat this process.

If things don't improve, call 911.

You need to 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.

Good options include:

  • Over-the-counter (OTC) glucose tablets or gels
  • 1/2 cup of juice
  • 1/2 a large banana
  • Three pieces of hard candy

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.

You may also take OTC Tylenol (acetaminophen) or Advil (ibuprofen) if the pain doesn't subside right away.

If you are concerned about your symptoms or the headaches don't subside with one of the quick fixes above, consult with your healthcare provider 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, call 911.

Keep your friends and family informed about ways they can act quickly to help you with a hypoglycemic episode.


Hypoglycemia can cause a dull, throbbing headache in your temples. These headaches often occur alongside other symptoms like blurry vision, fatigue, and confusion.

Hypoglycemia-induced headaches can be prevented by making sure your blood sugar levels don't drop. If you have diabetes, make sure it's well-managed. Regardless of the cause of your hypoglycemia, it's important to eat a healthy diet and avoid letting too much time pass between meals.

When you get a hypoglycemic headache, the most important thing to do is get your blood sugar back under control. If eating carbohydrates doesn't help, seek medical attention right away.

5 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. National Headache Foundation. Hypoglycemia.

  2. American Diabetes Association. Hypoglycemia (low blood glucose).

  3. National Institute of Diabetes and Digestive and Kidney Diseases. Low blood glucose (hypoglycemia).

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

  5. Centers for Disease Control and Prevention. Carb choices.

Additional Reading

By Collene Lawhorn
 Collene Lawhorn, PhD, is a neuroscientist and researcher specializing in neuropain.