4 surprising causes of headaches

Headaches are an unfortunate and painful fact of life. Often the culprit is obvious: a sinus infection, too much red wine the night before or screen time overload. But other times, the source of your headache is a mystery.

If headaches become chronic, you may panic and start to worry that it’s something bad, such as brain cancer. But don’t freak out — headaches are rarely a sign of a brain tumor. It’s much more likely that you just haven’t identified the trigger.

Here are several surprising causes of headaches you may not have considered.

You skipped your morning coffee

Was your morning so crazed that you didn’t have time for your usual mug of java? That could be why you’ve got a nagging headache. Regular caffeine drinkers can get a withdrawal headache if they don’t have enough caffeine, explains Ghazal Lashgari, MD. She’s a board-certified neurologist at Cedars-Sinai Medical Center in Los Angeles, California.

That’s because your body gets used to having caffeine every day. Over time, you may develop a dependence on it. If you suddenly drink less than your normal amount of coffee or tea, or skip it altogether, your body experiences withdrawal symptoms such as head pain.

Why? Caffeine narrows the blood vessels around your brain, so when you stop drinking caffeine, those blood vessels get larger. More blood flows through, putting pressure on the surrounding nerves, according to the Mayo Clinic.

Hot tip: If you’re trying to cut back on caffeine, take it slowly to fend off withdrawal headaches. Start by mixing in regular coffee with decaf or switching from dark roast to light roast. If you’re a tea drinker, try alternating regular tea with non-caffeinated herbal tea at first.

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You forgot to drink enough water

When your body doesn’t get the fluids it needs to function, you can get a dehydration headache. And summer is prime time for hydration issues. You’re spending more time outside, and temperatures are on the rise.

Dehydration headache pain can range from mild (a dull ache) to severe (sharp, pounding pain). You may feel it all over your head or in a single spot. This pain often appears along with other symptoms of dehydration such as:

• Dizziness
• Extreme thirst
• Dark urine
• Fatigue
• Muscle cramps
• Dry mouth

Dehydration causes your brain and other tissues to shrink, according to the Cleveland Clinic, When your brain shrinks, it pulls away from the skull and puts pressure on nerves. The result: pain.

The best way to resolve a dehydration headache:

• Rehydrate with small sips of water
• Rest in a cool, shady place
• Take an over-the-counter (OTC) pain relief medication such as acetaminophen (Tylenol^®) or ibuprofen (Advil^®, Motrin^®)

Your eyeglasses prescription needs updating

Your glasses or contact lenses can trigger a headache if the prescription is off. When your prescription is too strong or too weak, the muscle inside your eyes that controls your natural lens (called the ciliary body) has to contract to compensate, says Michael J. Shumski, MD. He’s an ophthalmology specialist at Magruder Laser Vision in Orlando, Florida.

Over time, this can cause eyestrain or headache symptoms. “This type of headache is typically described as mild or dull and often feels like a ‘pulling’ or an ‘eyestrain’ sensation,” Dr. Shumski says. Thankfully, these symptoms often go away once your prescription is corrected, he adds.

If you notice mild or dull headaches, visit your eye doctor for an exam. They can check that your prescription is still up to date. If it’s not, your eye doctor will give you a newer, more accurate prescription.

You ate food you’re sensitive to

For some people, eating certain foods can cause headaches. Common offenders include:

• Dairy
• Corn
• Wheat
• Cane sugar
• Yeast
• Citrus
• Processed foods
• Grain cereals

Most food-related headaches are caused by food intolerance. When you have a food intolerance, your body lacks the ability to digest certain proteins found in food. This results in symptoms such as:

• Nausea
• Stomach pain
• Gas or cramps
• Bloating
• Heartburn
• Vomiting
• Irritability or nervousness
• Diarrhea
• Headaches

To figure out if food intolerances are behind your headaches, start keeping a food diary. Record what you eat every day and when you experience symptoms. You may be able to trace your headaches to a specific source. If that doesn’t work, see your doctor.

Treatment options for headaches

OTC pain relievers: Most minor, infrequent headaches can be treated with OTC pain relievers such as acetaminophen or ibuprofen. That should be enough, says Dr. Lashgari.

Just keep in mind that more is not better. Be sure to stick to the recommended dosages on the bottle. Taking too much acetaminophen can cause liver damage, and overdoing it on ibuprofen can upset your stomach, according to Harvard Health Publishing.

Prescription medications: See your doctor if your headaches are constant and getting in the way of daily life. You might have migraines, a type of headache that causes severe throbbing pain, usually on one side of the head. Your doctor may prescribe medications to treat or prevent migraines.

There are medications taken at the first sign of a migraine attack to relieve pain and stop the migraine from getting worse. In addition, there are preventive medications you can take daily by mouth or every 3 months as an injection.

Natural remedies: Supplements such as magnesium, riboflavin (vitamin B2) and coenzyme Q10 (CoQ10) have shown promise for treating and preventing headaches and migraines, Dr. Lashgari says. But these supplements may interact with medications and cause side effects. Talk to your doctor before using any supplement to treat and prevent headaches or migraines.

Finally, get immediate medical attention if your headaches start feeling different or more intense than usual. Dr. Lashgari says these symptoms could be a sign of a serious medical issue:

• Weakness or numbness
• Sudden nausea or vomiting
• A change in vision, balance or speech

The good news is that most headaches are not an emergency. Once you identify the trigger, you should be on your way to getting the relief you need.

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Additional sources
Caffeine and headaches: Harvard Health (2019). “If you have migraines, put down your coffee and read this.”
Dehydration overview: Cleveland Clinic. “Dehydration headaches.”
Food allergies: National Headache Institute (2020). “Food allergies can cause headaches.”
OTC pain medications: Harvard Health Publishing (2020). “Acetaminophen safety: Be cautious but not afraid.”
Migraine medications: American Migraine Foundation (2018). “Understanding migraine medications.”