Image copyright Getty Images Image caption Daughter Kelly (left) has been helping her dad get back in the studio, she said

Rock star Ozzy Osbourne has revealed he has Parkinson's disease.

The Black Sabbath singer, 71, told US TV show Good Morning America he has a "mild form" and found out about it after suffering a fall last February.

Wife Sharon said: "It's not a death sentence but it affects certain nerves in your body. You have a good day, a good day, then a really bad day."

Ozzy added it was hard to tell whether the numbness symptoms he had were from the Parkinson's or the fall.

The singer said: "It's been terribly challenging for us all.

"I did my last show [on] New Year's Eve (2018). Then I had a bad fall. I had to have surgery on my neck, which screwed all my nerves."

He said he was now on medication for Parkinson's and nerve pain following the surgery he had after his fall.

Rumours had been circulating about his health, but Ozzy said: "I'm no good with secrets. I cannot walk around with it any more 'cause it's like I'm running out of excuses, you know?"

Image copyright Getty Images Image caption Osbourne has a US tour coming up in the spring

He added that he was grateful to his fans. "They're my air, you know. I feel better. I've owned up to the fact that I have... a case of Parkinson's. And I just hope they hang on and they're there for me because I need them."

It was his son Jack and daughter Kelly who first realised that something wasn't right with their dad. "The hardest thing is watching somebody that you love suffer," Kelly said.

What is Parkinson's disease?

The three main symptoms are involuntary shaking, slow movement and stiff and inflexible muscles

A person with Parkinson's can also experience a wide range of other physical and psychological symptoms, including depression and anxiety, balance problems, loss of sense of smell, problems sleeping and memory problems

Parkinson's disease is caused by a loss of nerve cells in part of the brain called the substantia nigra

Exactly what causes it is unclear - most experts think a combination of genetic and environmental factors is responsible

Around one in 500 people are affected by Parkinson's disease

Although there's currently no cure, treatments including medication and physiotherapy can help reduce the main symptoms

With advances in treatment, most people with Parkinson's now have a normal or near-normal life expectancy

Source: NHS

Jack, who was diagnosed with multiple sclerosis in 2012, said he could relate to his father.

"I understand when you have something you don't want to have - but if he wants to talk... and if not, I try to slip in information," said Jack.

Image copyright Getty Images Image caption Son Jack was diagnosed with MS in 2012

Ozzy said his health was improving. "I'm a lot better now than I was last February. I was in a shocking state."

Sharon said the next step was to consult doctors outside the US and explore other possible treatments.

"We've kind of reached a point here in this country where we can't go any further because we've got all the answers we can get here," she said.

"So in April, we're going to a professional in Switzerland. And he deals with... getting your immune system at its peak."

Ozzy had been due to go on the road in the UK with his No More Tours 2 in January 2019, but called off the shows due to ill health. He then postponed all his 2019 appearances following his fall.

He is due back on stage when his US tour starts in Atlanta, Georgia, on 27 May, before his rescheduled UK dates begin in Newcastle in October.

It was revealed back in 2007 that Ozzy had a condition called Parkinsonian syndrome - not Parkinson's disease - which also causes tremors.

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