Most migraines have triggers -- and if you can avoid the trigger, you can avoid the headache.

If you've never had a migraine, that may sound easy enough.

But as people who fight these headaches know too well, migraine triggers aren't always easy to spot, and they can be even harder to avoid. Anything from a nearby lightning strike to a certain smell could cause you to double over in blinding pain.

And now, new research finds one possible trigger that's practically everywhere: Bisphenol A (BPA), the dangerous hormone-like chemical used in plastics, can linings, ink and more.

In the study, rats prone to migraines were exposed to bisphenol A once every three days. Within 30 minutes of being hit with the chemical, they showed the classic signs of a migraine attack.

They slowed down, minimized their activity and tried to avoid light and noise (rats with migraines act much like people do).

It's not just rats. We've seen the link in humans, too, and for good reason. Migraines can in some cases be caused by a sudden surge in estrogen levels (which is why women are three times more likely than men to suffer from them).

And BPA, of course, is a chemical form of estrogen.

It's so much like estrogen that your body believes it's getting a hormone dose -- and if your migraines are estrogen-related, a shot of bisphnol A could be enough to trigger a headache.

On the other hand, when it comes to BPA, migraines might actually be the least of your worries.

BPA has been linked to obesity, diabetes, fertility problems, cancer, sexual dysfunction in adults, developmental problems in children and more.

The most common sources of exposure are food and drink. Just about anything in a can or plastic bottle can contain bisphnol A. Even foods and drinks from glass jars and bottles can contain BPA due to the sealant used in caps and lids.

You'll also find it in microwave trays -- so even BPA-free foods can get dosed with the chemical if you "nuke" them in a plastic container.

Don't trust packages that claim to be BPA-free, as many contain closely related chemicals that could be just as bad.

Stick to fresh organic foods instead. If it hasn't been in a package, it's unlikely to contain BPA.

I'm not done with migraine prevention yet. Keep reading for another common trigger you might not be aware of.