Billy Joel describes symptom of brain condition as "like being on a boat"

Two months after canceling his tour due to a brain condition diagnosis, Billy Joel says the health issue is not fixed, but that he feels good.

Joel, 76, revealed in May he had been diagnosed with normal pressure hydrocephalus, a condition when fluid builds up in or around the brain, disrupting brain function.

"It's not fixed, it's still being worked on," Joel told Bill Maher on the latest episode of Maher's podcast, "Club Random."

The "Piano Man" singer said the condition has affected his balance, a common side effect.

"My balance sucks. It's like being on a boat," he said. "It used to be called water on the brain."

Joel said "nobody knows," when Maher asked what causes the condition. About half of cases of normal pressure hydrocephalus are idiopathic, or happening for unknown reasons, according to the Cleveland Clinic.

"I feel good," Joel said. "They keep referring to what I have as a brain disorder, so it sounds a lot worse than what I'm feeling."

Joel also told fans not to worry in an interview with People.

"It was scary, but I'm okay," he told the magazine. "I just wanted to let people know, don't worry about me being deathly ill or anything."

Normal pressure hydrocephalus is usually treatable, health experts say. It is relatively uncommon, but is more likely to occur in people over the age of 65.