In a National Headache Foundation survey of some 170 headache patients, 46% reported having had sex-related headaches.

The survey, conducted on the National Headache Foundation's Web site during December, included 182 people, mainly women aged 21 and older.

Nearly all participants - 96% - reported getting headaches from any cause. The same percentage said they're sexually active.

When asked if sex has ever triggered a headache, 54% said no and 46% said yes. Sex-related headaches most often occurred after sex, the survey shows.

Among people reporting sex-related headaches, about 40% said they've cut back on their sexual activity because of their sex-related headaches, and only 12% said they've talked to a doctor about their sex-associated headaches.

That doesn't mean that sex is their only headache trigger. Among people who reported sex-related headaches, 42% reported having had no more than six of those headaches.

Not everyone got headaches from sex. In fact, 20% of participants noted sex eases their headaches and 6% report having sex more often for the headache relief.