What’s really behind your ponytail headaches?

When you sign up for a HIIT class or bootcamp, you’re expecting to feel the burn from your burpees and mountain climbers, but from your ponytail? Not so much.

Ponytail headaches are definitely a real thing. A 2004 study out of London found that fifty women out of a group of 93 experienced pain on their heads while wearing ponytails. These types of “extracranial headaches” usually come about because of scalp sensitivity, and are reportedly different than the sorts of brain-buster (or, “intracranial”) headaches you might be used to.

“If someone is wearing a hairstyle that is particularly tight, when it’s pulled back that tightly, the pain sensors in the scalp become constantly sensitized or activated,” explains Wade Cooper, DO, a Michigan-based neurologist.  “So over time, that starts to generate a pain signal and the scalp becomes achey and sore just from that mechanical pulling of the hair.”

This sensation is called Allodynia, which means that something that is usually comfortable—like pulling your hair back into a ponytail—can start to feel feel uncomfortable. If you’re reading this and thinking, “this has never happened to me in my life,” it’s NBD. According to Dr. Cooper, the phenomenon is more common in people who have migraines or other pain disorders (like fibromyalgia) because their nervous systems are generally more sensitive to any kind of stimulus.

“The area of the scalp, neck, and face can all act as triggers for people who are susceptible to migraines, and so it is likely that tension due to a ponytail would act as a migraine trigger in certain people,” says Paul Booton, a headache specialist at the National Migraine Centre in the UK. “It is also the case that a great deal of migraines remain undiagnosed particularly in people who have them less severely.”

Meaning: You might get a headache from a ponytail and brush it off, but it actually could be a sign of a migraine.  After all research shows that 85% of chronic migraine sufferers are women (18% of women experience at some point, compared to only 6% of men).

According to the pros, the best way to deal with any sort pony-induced pain is to let your hair down. If you don’t feel better within an hour or two, or if you start to feel other symptoms like light or sound sensitivity or nausea, it may be a sign of an untreated migraine, so you should check in with a doctor, stat.

Who says ponytails are the only way to keep your hair out of your face during a workout? Check out these three sweat-friendly hairstyles, or just commit to the trusty ol’ “messy updo” and call it a day.