Popular culture always sends us mixed messages about sex. First there was the old cliche of "not tonight dear, I have a headache," implying sex makes pain worse.
Then Marvin Gaye turned the tables on the sex-pain connection with his 1982 song "Sexual Healing."
So, who is accurate — Gaye or the tired spouse? Does sex make or break a headache? Well both, say headache researchers, depending on the person and the headache.
Much of sex's influence on a headache remains shrouded in mystery, but doctors know a little and are discovering more.
In 1988, a forthright woman in a headache treatment study inspired an Oklahoma doctor to question the sexual healing of migraines.
"This lady said 'I really don't need a pill, I need a guy's phone number," said James Couch, a neurology professor at Oklahoma Health Sciences Center. The patient told Couch she had trouble curing her headaches since her husband had divorced her and she'd signed up for a pain treatment study.
Couch thought this was interesting, in a scientific way, of course. "A physiologic process — the climax — is turning off another physiologic process," said Couch.
So he asked 84 other female migraine patients if they ever had sex during a headache and, if so, what happened?
Two out of three women reported having sex during a migraine — those intense debilitating headaches characterized by nausea and sensitivity to light, or sound. Doctors estimate about 18 percent of women and 9 percent of men get migraines often.
Of the women who tried sex with a migraine, 61 percent reported some sort of relief. Not bad, compared to the latest migraine drugs called triptans, which might soothe 60 percent to 80 percent of headaches, says Couch.
Perhaps more intriguing to Couch was the reports that sex could sometimes stop a migraine dead in its tracks, instead of slowly dulling the pain. More than 20 percent of women reported that sex cured their migraines, while triptans might cure migraine in 30 percent of patients, says Couch.
"Four women said it literally stopped the headache, period," said Couch. "No matter when the headache occurred, it stopped the headache cold."
Researchers may guess why sex can cure a migraine, through endorphins and other pain-relieving hormones released during orgasm, or through the stimulation nerves that trigger pain relief in childbirth. But, says Couch, no one really knows why sex works.
"I haven't really figured out how to follow up with that study," said Couch with a laugh. He added that he won't start prescribing sex as a cure.
While sex might help some migraines — at home — sex can be a trigger that causes headache in up to 10 percent of all people who suffer from migraines, says Randolph Evans, clinical professor of neurology at Baylor College of Medicine.
And sex can trigger other kinds of headaches, especially in men.
One type of headache starts as a dull ache in the head and neck. The pain may feel mild at the beginning of sexual activity, but gets worse the longer the couple continues, says Evans.
Another type of headache — the orgasmic headache — is a sudden, severe "explosive" headache that builds just before or during orgasm. The intense pain may last for several hours afterward.
"It's a big issue with some people," said Evans. Luckily, the explosive headache, called coital cephalalgia, only occurs in about 1 percent of men and often resolves itself spontaneously before becoming a pattern.
But as many men grow older, they face a new threat of headache with sex — Viagra.
Headache is listed as a side effect of Viagra and other erectile dysfunction drugs. Obviously, says Evans, men will get the headache side effects of the drugs just when they wanted to get the good effects.
Because sex can sometimes be a cure, and sometimes be a cause for a headache, it's largely up to headache sufferers to decide what works for them.
Preventing headaches in the first place can go a long way. Evans suggests tracking migraine triggers, getting regular sleep and exercising regularly, even if it's only walking a mile a day.
"I doubt that sex is a reliable treatment for headache," said Evans. "You can't grab somebody in the office and say, 'Hey, it's a medical emergency!'"