It's an orgasm. Followed by a massive migraine. It's called coital cephalgia, or orgasmic cephalalgia, orgasmic thunderclap, orgasmic migraine, coital headaches or, um, sex headache. And people don't really talk about it.
I had never heard of this awful phenomenon until it happened to a friend of mine: she described it as horribly painful, kind of scary, and deeply traumatic. In her words, "I haven't gotten back in the saddle since." (Of course, she was one of the unlucky few who experienced 36 hours of pain after her "explosive headache.") What kind of fate would punish an amazing orgasm with a head-splitting migraine? Well, they don't know — only that it happens to 1% of the population...or, rather, that 1% of the population have sought treatment for it. Of that number, men are far more common...but this, too, seems like it might have something to do with social taboos.
If you believe the anecdotal evidence of the Internet, plenty of women are getting these sudden, blinding migraines — and are eager for answers. But it's not hard to see why people wouldn't want to talk about it: to admit to not just sex but orgasm is still ludicrously difficult in our culture. Forget about prior generations who must have felt they were experiencing swift punishment for daring to indulge carnal desires! Yes, when you look for it, there is information out there, much of it reassuring. But I found it worrisome that this was something I'd never heard of — and for the friend who experienced it, apparently it was really alarming.
But here is what they do know: these headaches fall into three basic categories. It can occur before orgasm, immediately upon coming (a la my friend) or directly afterwards. The pain can be dull or the knife-like stabbing she described. They can last a few minutes, hours or even days. And while they're not generally dangerous, like anything they can herald another problem, so if they're habitual or really bad, see a doctor. To be safe, see one the first time you experience one.
Oh, and last but not least, "they're not a joke." That's actually the name of one study of the phenomenon. Because we still find discussing sex inherently funny, and embarrassing. And I'm convinced that there are people out there who have experienced this and were scared, but were disinclined to learn more or admit to it. But if I get a blinding headache immediately after sex, I'd much rather know what was going on — or at least that I wasn't the only one.
What If The ‘Sexual Headache' Is Not A Joke? [British Journal of Medical Practitioners]