Ozzy Osbourne has had to cancel a European tour so that he can receive treatment for a nervous tremor.
The British singer said the tremor had almost destroyed his life.
He said he had been undergoing tests for the last three weeks for an involuntary shuddering which had become "markedly worse over the last two years".
His European tour had been scheduled to begin in Dublin on 22 October.
The former Black Sabbath singer found renewed fame with the MTV show The Osbournes, which propelled him to a worldwide audience.
"I was at the point where it felt as if this problem was
practically destroying my life along with my self-esteem," he said.
He added: "I was no longer comfortable being around people, which, as
you can imagine, is not the best trait for a performer."
There had been concerns he was suffering from Parkinson's Disease, but following weeks of tests doctors have now ruled that out.
Dr Allan Ropper, the chairman of the neurology department
at Tufts University in Boston and Osbourne's doctor, said
tests had showed Osbourne did not have Parkinson's disease.
He said his tremor was "coming under control with medication".
"Unfortunately, one of the side effects of the medication
is dry mouth, which greatly impairs the voice.
usually subsides after three to four weeks, but the downside is
that this will definitely affect Mr. Osbourne's ability to sing
at this time."
His tour will now be rescheduled for early 2004, a
statement from the performer said.