What to know about normal pressure hydrocephalus as Billy Joel cancels tour

Billy Joel announced Friday that he was diagnosed with normal pressure hydrocephalus after having trouble with his hearing, vision and balance.

The brain disorder that forced Billy Joel to cancel his concert tour can cause trouble walking and thinking straight — but is often treatable and can even be reversed, doctors said.

A post on the 76-year-old singer’s Instagram on Friday said that he was recently diagnosed with normal pressure hydrocephalus and that concert performances exacerbated problems with his “hearing, vision, and balance.”

The condition is relatively uncommon, according to the Cleveland Clinic, affecting “about 5.9% of people over 80.”

It’s most commonly diagnosed in older adults, usually showing up around age 70.

The human body is constantly trying to keep a steady level of cerebrospinal fluid to cushion the brain and spinal cord, either by making more or absorbing it.