WASHINGTON — Most migraine-sufferers know that stress can bring on the malady. But some might be surprised to learn that a sudden lack of stress can trigger them, too.

Going from sad or nervous to happy or relaxed can boost the risk of a migraine by 20 percent, according to a study detailed by Health Magazine.

To avoid a big swing in stress hormones, experts recommend working to relax by taking frequent breaks or doing yoga, for example.

Sex and intense physical exertion can trigger migraines. That’s most common with younger and mid-life men who doctors sometimes prescribe beta blockers to help.

Also on a list of migraine triggers is lightning. Study authors speculate it might have to do with blasts of electromagnetic waves or lightning-boosting production of ozone or fungus spores.

Many migraine sufferers are sensitive to changes in temperature, humidity and barometric pressure related to the weather.

A study from Canada shows spikes in migraines also occur when wind blows faster than 23 mph.

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