I'm a 61-year-old woman who developed an excruciating headache the last time I had sex and achieved orgasm. Do you have any ideas what could have caused this?
What you're describing is most likely a "benign orgasmic/sex headache." It is caused by a swelling of the arteries of the brain, somewhat like a migraine headache. It falls under the general category of "exertional headaches," and people who suffer from migraines tend to get sex headaches more often. And men seem to be affected four times as often as women.
With intense exercise or the physical activity associated with sex, the muscles of the scalp, head and neck require more blood flow. This swelling can cause headache pain. The pain is usually sudden and throbbing, and typically occurs just before or right after orgasm. Some people experience this pain regularly with sex. For most, however, there's no predicting when it will occur. A general rule: the more intense the sex, the greater the likelihood that a person predisposed to a sex headache will experience one.
That said, exertional headaches can be a sign of a serious medical problem known as a subarachnoid hemorrhage, or bleeding from the rupture of a vessel in the brain. So it's important that any sudden headache like this one - or a headache after lifting weights, coughing, sneezing, bowel movements, or running - be checked out by your family doctor or a neurologist. An MRI or CT scan of the head is a critical part of that workup.