Here's why summer summer heat can trigger migraines; experts offer advice on how to cope

Experts say heat waves have become more frequent and lengthier, which can be a specific headache trigger for so many people in Southern California.

The American Migraine Foundation says an estimated 39 million Americans live with migraines. Half of those say the weather, especially hot weather, is a factor.

Extreme heat during 27-year-old Caitlin Cavanaugh's college freshman year set off her lifelong journey with migraines.

"It actually started in the summer," Cavanaugh said. "I'd feel sharp pains in my head, I would get blurred vision and I really couldn't be in light."

Although doctors say the onset of a migraine is a mix of compounding environmental factors, hot weather can be a catalyst.

"Heat makes your blood vessels get small if you're dehydrated," Dr. Clifford Segil, a neurosurgeon with Providence Saint John's Health Center, explained.

Soaring temperatures come with a change in barometric pressure, direct sun exposure and humidity are all conditions the body reacts to, Segil said.

"There's blood vessels between your skull and your brain and your meninges in this shock absorber part of the brain, and when the blood vessels change diameter it causes this throbbing pain," he said.

Migraines are a chronic neurological condition that comes and goes due to stress, the environment and what you eat.

"The most important thing in the management of migraines is to avoid triggers, to try to be prophylactic and preventive when you know it's going to be hot to increase your fluid intake," Segil said.

Besides staying hydrated and avoiding triggers, Segil says over-the-counter pain medications can help. But he warns that if you need to take them more than three days in a row, don't -- because you could end up with rebound headaches.

"If you're miserable, please come, see a neurologist so I can give you medications that are both rescue and daily medications to make your life easy," Segil said.

Cavanaugh keeps her migraines in check with a class of medications called triptans. So, when the temperature starts to rise again, she's ready.

"I think staying hydrated is like the number one thing," she said. "I have a Stanley cup at work, and I drink four or five of them a day, and that's just how I get through my day to day."

One other thing to keep in mind: Experts say lack of sleep can contribute to a headache. And it can be especially hard to sleep when it's hot outside.