Barometric pressure and headaches

“My head hurts before it rains.” “Every time a storm rolls in, I end up in bed.” Headache specialists hear this every day. Some people really do get headaches when barometric pressure changes. In studies, about half of people with migraine say weather is one of their triggers. This article explains why pressure changes may bring on a headache, how big a drop matters, and what you can do on days when pressure falls.

Why can falling pressure cause a headache?

No one knows exactly yet. One leading explanation is that the inner ear senses the change in pressure and the autonomic nervous system responds. The inner ear holds the organs that help you keep your balance. When they sense a pressure change, the sympathetic nervous system becomes more active. This may change the state of blood vessels and nerves and make a headache more likely. Animal studies support this idea, but it hasn't been proven in people.

Another important point: days when pressure drops often bring other triggers too. When a low-pressure system or a front moves in, the temperature can change quickly, humidity rises, and bad weather can throw off your sleep and daily routine. Migraine tends to start when several triggers pile up, so it's often the combination, not pressure alone, that sets off an attack.

How much of a pressure drop matters?

Average sea-level pressure is about 1013 hPa (29.92 inHg). Many people assume only big drops matter, like the 20 to 30 hPa (0.6 to 0.9 inHg) drop of a strong storm. But two studies from Japan found more migraine attacks with smaller drops. Both studies (2011 and 2015) found that attacks increased when pressure was about 6 to 10 hPa below average, around 1003 to 1007 hPa (29.62 to 29.74 inHg). Both were small, so they don't show that a headache will always start below a certain number. Still, it's useful to know that your body may react even when pressure is just a little lower than usual.

Zutsu Note's barometric pressure forecast by state uses these numbers to rate each day as Caution, Mild, or Stable in two ways:

Many people react more to how much the pressure changes than to the number itself, and some get headaches when pressure rises, not just when it falls. Whether you're sensitive to low pressure or to changes differs from person to person, so the surest way to find out is to keep a record, as described below.

What kind of headache does the weather bring on?

The most common is migraine: a throbbing pain that gets worse when you move, often with nausea and sensitivity to light and sound. Some people find that tension-type headache, a tight, pressing pain around the head, also gets worse with the weather.

You may see terms like “weather headache” or “barometric pressure headache.” These aren't official diagnoses. They describe headaches that come on with weather changes, and in most cases the headache itself is migraine or tension-type headache. So the main approach isn't the weather itself but treatment that fits your type of headache. Some people also notice dizziness, a plugged feeling in the ears, tiredness, or sleepiness when pressure changes.

What you can do on low-pressure days

1. Know ahead of time

If you know a drop is coming, you can adjust your plans and your sleep. Zutsu Note's barometric pressure forecast shows today's hourly pressure for each state and the outlook for the week ahead, updated four times a day.

To see how many people have a headache right now, check the real-time headache map. It combines logs from Zutsu Note users with taps on the “I have a headache now” button and updates every 10 minutes.

2. Don't let triggers pile up

• Keep your sleep and meal times regular. Too little sleep, too much sleep, and skipped meals are common triggers, just like pressure.
• Drink fluids throughout the day. Dehydration can also bring on an attack.
• Go easy on light and screens. On stormy days, people often spend more time indoors looking at screens. Light can make migraine worse, so dim your screen and take breaks.
• Keep your neck and shoulders warm. When the temperature drops, some people feel better just by keeping their neck warm.

3. Plan how to use your medicine with your doctor

For migraine medicine, the general rule is to take it early, when the pain is just starting. Whether to take something ahead of time because pressure is about to drop depends on the medicine, so don't decide on your own. Ask your doctor. If you take headache medicine, over-the-counter or prescription, on 10 or more days a month, the medicine itself can start causing headaches. If you notice you're taking more medicine in months with bad weather, talk to your doctor early.

4. Pick gadgets by what works for you

Some people use pressure-regulating earplugs, massage around the ears, or cold or warm packs on days when the weather turns. Results vary a lot from person to person, and few of these have been tested in studies.

How to tell if your headaches are linked to pressure

“I think it's the weather” and “it was the weather” aren't the same. There's one way to find out: keep a record of your headache days next to the pressure on those days. With 1 to 2 months of records, you can see whether your headaches really come on days when pressure drops or on low-pressure days, or whether poor sleep or your period matters more.

This record is also valuable for your doctor. If it shows migraine that gets worse with the weather, it's easier to talk about treatment, including preventive medicine.

When to see a doctor

• You have headaches several times a month, whether or not the weather changes.
• You take headache medicine on 10 or more days a month.
• Headaches make you miss school or work, or leave early, at least once a month.
• Get emergency care right away for a sudden, severe headache, a headache unlike your usual ones, or a headache with fever, weakness or numbness in an arm or leg, or trouble speaking. Call 911 or go to the nearest emergency room.

Migraine can be treated. Preventive medicines reduce attacks, and acute medicines work quickly during an attack, which can bring you closer to days that don't depend on the weather. To find a headache specialist near you, try the American Migraine Foundation's doctor finder.

Studies we used

• Prince PB, et al. The effect of weather on headache. Headache. 2004;44:596-602.
• Kimoto K, et al. Influence of barometric pressure in patients with migraine headache. Internal Medicine. 2011;50:1923-1928.
• Okuma H, et al. Examination of fluctuations in atmospheric pressure related to migraine. SpringerPlus. 2015;4:790.
• Hoffmann J, et al. Weather sensitivity in migraineurs. Journal of Neurology. 2011;258:596-602.