How common is a CSF leak?

How common is a CSF leak?

Having a CSF leak causes a drop in fluid pressure inside your head. That causes a condition known as intracranial hypotension (“intracranial” means “inside your skull” and “hypotension” means “lower than normal pressure”). Intracranial hypotension is a rare condition, and about 5 people out of every 100,000 have it.

However, it's very likely that CSF leaks happen more often than that number suggests. Experts don't know exactly how common CSF leaks are because they're difficult to diagnose. It's also common for healthcare providers to misdiagnose a CSF leak as another condition, like migraine, sinus infections or allergies.