Table of ContentsView AllTable of ContentsCausesSymptomsTreatmentPrevention
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Table of Contents
Causes
Symptoms
Treatment
Prevention
A hungerheadacheis one you get from not eating. Researchers don’t know exactly how not eating can give you a headache, but it may have something to do with falling blood sugar levels.
Also called a fasting headache, a hunger headache may come on suddenly or slowly, and the pain is constant and occurs on both sides of your head. A hunger headache generally resolves within 30 minutes after eating.
This article explains the causes and symptoms of hunger headaches and how to treat and prevent them.
Verywell / Julie Bang
Hunger headaches occur when your body is deprived of something it needs—specifically, food, water, or caffeine.
Blood Sugar Levels
Low blood sugar, also known ashypoglycemia, occurs when the body’s glucose levels are 70 milligrams per deciliter (mg/dL) or below. When this happens, you may experience symptoms such as dizziness, shakiness, and confusion.
When your blood sugar levels drop,
Hypoglycemia often occurs in people withdiabetes, especially those with type 1 diabetes, but having low blood sugar does not mean you have diabetes. People with nondiabetic hypoglycemia are generally recommended to go no more than three hours between meals.
One study demonstrated that hypoglycemic patients are more likely to be hungry and have headaches, compared to non-hypoglycemic patients.
With type 1 diabetes, the pancreas cannot produce insulin. Type 2 diabetes occurs when the body has trouble responding properly to insulin and regulating glucose levels. If someone with type 2 diabetes takes too much insulin, they may experience low blood sugar.
Dehydration
When your body does not perform basic functions at optimal levels, it will start to conserve energy. This can result in the constriction (narrowing) of blood vessels, which may lead to a headache.
Simple Tricks to Drink More Water
Caffeine Withdrawal
Caffeine consumption causes vasoconstriction (narrowing of blood vessels) and blocking of adenosine receptors, which cause our feelings of alertness. The blocking of adenosine receptors causes more to form.
Ahungerheadache causes a squeezing or pulsating feeling, rather than a throbbing headache. You will feel the pain on both sides of your head. It may feel like you have a vise around your head.
The pain is usually mild or moderate. You may feel it at your temples or the back of your head and neck.
If you experience low blood sugar, follow the 15–15 rule: consume 15 grams of carbohydrates, wait 15 minutes, and measure your blood sugar level again. If your blood sugar is still below 70 mg/dL, repeat the steps until your blood sugar reaches 70 mg/dL.
If your blood sugar gets low often, you should carry healthy snacks with you at all times and apply the 15–15 rule to get your blood sugar back to normal when it gets low. These snacks should contain carbohydrates. An alternative is to carryglucose tablets, which are chewable supplements that quickly increase your blood sugar.
If you experience a caffeine-withdrawal headache, it is important to stay hydrated and taper your caffeine intake. You can also try drinking low-caffeine beverages, such as teas with low or no caffeine and decaf options.
If you have type 2 diabetes, make sure to wait at least 15 minutes after a meal before testing your blood sugar to make sure you do not inject too much insulin and cause hypoglycemia.
To avoid dehydration headaches, increase your water intake. Consider adding sugar-free flavored drops to your water if you prefer it to have a taste.
To avoid caffeine withdrawal headaches, avoid consuming large amounts of caffeine. Experiment with low- or no-caffeine versions of your favorite drinks, or try something new. Drinking water can also help prevent caffeine headaches.
Summary
You may experience a hunger headache if you haven’t eaten or drunk water in a while or are experiencing caffeine withdrawal. Falling blood sugar levels release hormones that trigger the blood vessels to constrict (narrow), causing constant pain that usually occurs on both sides of the head.
If you experience a hunger headache, try alternating between consuming 15 grams of carbohydrates and waiting 15 minutes until your blood sugar reaches 70 mg/dL. Eating and drinking water regularly and avoiding large amounts of caffeine (or tapering yourself off of it) can help prevent hunger headaches.
Correction-October 19, 2023:This article was updated to clarify that the 15-15 rule recommends consuming 15 grams of carbohydrates, not 15 milligrams.
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Library of Medicine.Physiology, fasting.
Seattle Children’s Hospital.Headache.
Kalra S, Mukherjee JJ, Venkataraman S, et al.Hypoglycemia: The neglected complication.Indian J Endocrinol Metab. 2013;17(5):819-834. doi:10.4103/2230-8210.117219
Sigmon SC, Herning RI, Better W, Cadet JL, Griffiths RR.Caffeine withdrawal, acute effects, tolerance, and absence of net beneficial effects of chronic administration: cerebral blood flow velocity, quantitative EEG, and subjective effects.Psychopharmacology (Berl). 2009;204(4):573-85. doi:10.1007/s00213-009-1489-4
American Diabetes Association.Low blood sugar (Hypoglycemia).
American Migraine Foundation.Understanding caffeine headaches.
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