7 Weird Headache Triggers

Headaches are like hurricanes. Experts try to predict when they'll happen and how severe they'll be, but your throbbing head doesn't always play by the rules. Complicating the issue is the fact that the causes of a headache are different for everyone. For one person, strong perfume may be a trigger. For another, chocolate completely does her in. But after decades of research, science has pinned down some of the most common explanations for your headaches. And some of those explanations—like these 7—are just plain weird.   

MORE: 5 Natural Remedies For Headaches

Not tonight. I have a headache. It's a common (and commonly joked about) excuse long-term couples employ when they're not in the mood. But one in 100 people may experience a sudden or slow-building headache during sex, shows a study in the British Journal of Medical Practitioners. "Orgasmic headaches" are more common among men, and could be the result of sudden spikes in muscle contraction and blood pressure brought about by sex, the UK study team speculates.   

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Severe dehydration—like after a night of heavy drinking—causes major head pain. But even a slight drop in your hydration levels can cause headaches while also damaging your mood and ability to think clearly, shows a study from the University of Connecticut. When you pop that headache pill, it might be the water that actually relieves your pain, the study suggests.  

No, this isn't about radio waves and radiation. Staring at a screen—especially a screen that's positioned close to your face—can strain your eyes to the point that your head starts aching, shows research from the Journal of Clinical and Diagnostic Research. The muscles in your eyes work harder to focus on things that are close up, as opposed to far away. And more research shows bending your head and neck down to stare at a phone can also cause pain. (Whether you're on your computer or a cell, experts say taking a 20-second break to look at something at least 20 feet away can help relieve your headache.)

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You work your butt off all week. Come Saturday you sleep in, kick back, and...nurse yourself through a mini-migraine? If you normally drink coffee or caffeinated tea in the morning, going 24 hours without your fix can trigger headaches, according to the National Headache Foundation. (Too much caffeine can also launch a headache.) If you want to cut back on (or cut out) caffeine, it'll take about seven days for your withdrawal headaches to subside.

Your head starts to throb at the worst possible time—right when you NEED to get things done for a big work deadline. It's no coincidence. Stress, whether from work or your personal life, contributes to the onset of headaches—especially tension headaches, shows a study from Germany. While the links between stress and headaches are complex, the study authors say yoga can help fight stress, and so may safeguard your noodle.  

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Stress is a headache kick-starter. But while sitting in traffic is stressful (especially if you're running late), it may not be the reason for your throbbing temples. Vehicle exhaust releases nitrogen dioxide (NO₂) into the air. And research from both Canada and Israel has linked NO₂—by stoking inflammation and constricting blood vessels—to higher rates of headaches.

Stormy days have been linked to higher rates of headaches. And, again, nitrogen dioxide may be the culprit. The electrostatic reaction that results in that bright flash of light produces NO₂. (In fact, lightning is the greatest non-man-made source of atmospheric NO₂, concludes a recent NASA report.)

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