An orgasm is supposed to be the best part. For some women, it comes with a headache so bad they end up Googling “is this a brain aneurysm” or finding themselves in the ER.The medical term is Primary Headache Associated with Sexual Activity, or PHASA, and it affects an estimated 1-1.6% of the population, according to population-based studies. That sounds small until you factor in how underreported it is. “Sexual headaches are not uncommon, though many people are hesitant to talk about them,” neurologist Nestor Galvez-Jimenez told the Cleveland Clinic. “We see these more often than you might think, both in our practice and in the emergency room.”On Reddit’s r/WomensHealth, a recent thread on the subject drew lots of women with the same story. One described the headache as the worst of her life, a “pounding all over my head for 30 minutes” that hit hardest during back-to-back orgasms. Another called it “explosive” and “excruciating.” A third noticed the headache coming on before orgasm the following day and stopped midway to avoid it. It was a dull pain, but still there. Some Women Are Getting Explosive Headaches During OrgasmThe physiology isn’t fully understood, but the working theory involves a cascade of cardiovascular responses. During sex, heart rate and blood pressure climb. Blood vessels in the brain dilate. The muscles in the head, neck, and shoulders tighten. “Here’s what we think happens,” Dr. Galvez-Jimenez explained. “All of these reactions can add up to headaches that, for some people, are very sudden and severe.” Sex is a form of physical exertion, and for people who are susceptible to exertion headaches, the build-up toward orgasm can be a trigger.Hormones complicate things even further. Clinical sexologist Ness Cooper told Metro that some people have sensitivities to hormonal spikes and dips during sex, including prolactin and estrogen. “For some, it’s not an off-balance, but a sensitivity to these hormones which can be activated during orgasm, which can cause changes to the vascular system and then lead to headaches.” Serotonin fluctuations post-sex can also tip the balance. Pre-existing migraine history, dehydration, fatigue, and alcohol all increase susceptibility.Positions that strain the neck or engage the pelvic floor heavily are more likely to set it off. People who get these headaches consistently have had some luck adjusting angles, adding pillow support, or taking ibuprofen about 30 minutes before sex.If the headache is sudden and explosive and hits its peak within seconds of orgasm, especially the first time, go to the ER. That could mean a ruptured brain aneurysm and needs to be taken seriously. For most people, PHASA is benign if miserable. The strange coda to all of this: orgasms can occasionally fix tension headaches by releasing muscle tension and stress. Aren’t bodies fun?The post The Scary Reason Some Women Get Sudden Headaches During Sex appeared first on VICE.