Iconic American actor and director Alan Alda, famous for playing Hawkeye in the long-running TV comedy M*A*S*H, has revealed he has Parkinson’s disease.

The six-time Emmy Award winner said he was diagnosed three-and-a-half years ago, but had only decided to speak about it now.

Alda said he had decided to talk publicly about his diagnosis when he began to exhibit symptoms of the disease.

“I’ve had a full life since [the diagnosis]. I’ve acted, I’ve given talks, I help at the Alda Centre for Communicating Science at Stony Brook, the 82-year-old actor told CBS This Morning show.

“I started this new podcast. And I noticed that – I had been on television a lot in the last couple of weeks talking about the new podcast – and I could see my thumb twitch in some shots and I thought, it’s probably only a matter of time before somebody does a story about this from a sad point of view, but that’s not where I am,” he said.

NEW: Actor @AlanAlda just revealed he has Parkinson's disease. The award-winning actor says he was diagnosed with the disease three and a half years ago. https://t.co/cYba2YKewS (via @CBSThisMorning) pic.twitter.com/OpIUBvCKWi

— CBS News (@CBSNews) July 31, 2018

Alda said he went to his doctor to ask for a scan when he suspected he might have had the disease after reading a New York Times article.

“I read an article by Jane Brody in the New York Times that indicated that if you act out your dreams, there’s a good chance that might be a very early symptom where nothing else shows,”

“I was having a dream that someone was attacking me and I threw a sack of potatoes at them, but what I was really doing was throwing a pillow at my wife.”

“This is not to short-change people who are suffering with really severe symptoms. Symptoms can get very bad, and their families can suffer.

“But in the very beginning, to be immobilised by fear and think the worst thing has happened to you … you still have things you can do.”

I decided to let people know I have Parkinson’s to encourage others to take action. I was Diagnosed 3 and a half years ago, but my life is full. I act, I give talks, I do my podcast, which I love. If you get a diagnosis, keep moving!
More>> pic.twitter.com/zHrNxvlwcS

— Alan Alda (@alanalda) July 31, 2018

Alda recommended to anyone diagnosed with the disease to “keep moving”, saying he takes “boxing lessons 3 days a week, play singles tennis twice a week, and take a mild pill – all Dr. recommended”.

“I even juggle a little. And I’m not entering dementia. I’m no more demented than I was before.

“Maybe I should rephrase that. Really, I’m good.”

-with AAP