Arizona resident Joe Nagy had a problem.
After spending a year suffering from a runny nose he attributed to allergies, even when it wasn't allergy season, he decided to see a doctor.
But instead of getting a prescription antihistamine, the doctor told him his brain fluid was leaking.
"You don't really think about it, but our brains are really just above our noses all of the time," says Barrow Neurological Institute neurosurgeon Peter Nakaji.
"This is one of the more common conditions to be missed for a long time... because so many people have runny noses."