When fluid builds up around or inside your brain and inhibits typical functioning, it results in normal pressure hydrocephalus, or NPH, according to the Cleveland Clinic. This may lead to difficulties thinking and concentrating, as well as impair movement and memory. The condition may be reversible, and its symptoms could look a lot like dementia.

Billy Joel, the arena-filling Everyman singer-songwriter, has canceled all of his upcoming concerts, including a large-scale tour scheduled for this year and next, because of a brain disorder known as normal pressure hydrocephalus, he announced on Friday.