You wake up in the morning, look in the mirror, and — it’s hopeless. No matter what you try and do, your hair just won’t go the way you want it to. You’re going to have a “bad hair day” — and it’s likely going to make your day a bit cloudy. Of course, it’s not that big of a deal — beyond the fact that it’s something that can be fixed by wearing a hat, it’s not a reflection on your reputation or anything like that. And, despite the fact that WebMD (comically?) has a four-page (!) article titled “Surviving a Bad Hair Day,” hair that won’t give way to a brush isn’t some sort of rare illness, right?

Well… it can be. It’s unlikely, but you may have something called “Uncombable Hair Syndrome.”

Identified in 1973 by a team of French researchers, the malady is not all that worrisome unless you have designs of being an adolescent fashion model. The only problem associated with the condition is the uncombable hair itself; there are no other associated medical issues. People with the condition, as NBC News summarizes, have typical hair in general, but there are blonde clumps that do not seem to play nicely with the comb: “affected hair is dry, curly, brittle, and progressively uncombable,” as seen above (via Wikipedia). As one dermatologist further explained to NBC, “Normally, hair is quite pliable. You can run your fingers through it; it will bend easily when you comb it. But this makes the hair very difficult to comb. It just won’t bend.”

The condition is believed to be genetic, following what is called an “autosomal dominant inheritance pattern,” but researchers have yet to isolate the gene upon which the mutation is carried as of 2015. And the condition is also very rare, with known cases numbering in the hundreds. That may be a function, however, of the relative unseriousness of the syndrome — how often do you go to the doctor over difficult hair? — and the fact that almost all those affected are under the age of 12. So unless you’re not yet a teenager (and therefore, unlikely to be freaking out about your hair), you may let it go unnoticed.