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The Ache: Some 38 million Americans suffer debilitating migraines, often brought on by “triggers,” such as hormonal changes, lack of sleep, certain foods or weather changes.

The Claim: New smartphone apps analyze input from migraine sufferers to identify their personal triggers and rank them by importance. Makers of the apps hope they eventually will be able to forecast when a migraine may be on its way.

The Verdict: The apps show promise in taking the guesswork out of identifying migraine triggers, and also in helping pinpoint behaviors, such as a good night’s sleep, that protect against an attack, scientists say.

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David Dodick, a professor of neurology and director of headache medicine at Mayo Clinic, in Phoenix, says some migraine sufferers may not need the apps if they have obvious triggers, such as alcohol use or menstruation. More likely to benefit are people whose migraine attacks occur when several triggers “stack” on top of each other. “For example, you’re an accountant and it’s tax time, you’re stressed, sleep-deprived and you have a glass of wine to unwind. All those factors together have pushed you over the edge,” suggests Dr. Dodick, who is president of the International Headache Society.

The software in the apps is designed to refine its conclusions about you with each new data point entered, says Stephen Donoghue, vice president clinical development at Curelator Inc., of Cambridge, Mass. The company’s Curelator Headache app, available for the iPhone, costs $50 for the premium version. People can get a coupon from many neurologists to get the app free if they agree to allow their data to be used anonymously in the company’s research.

Click for more from the Wall Street Journal.