Alan Alda, who starred as wise-cracking army doctor Hawkeye Pierce in the long-running television comedy series "M*A*S*H," revealed on Tuesday that he has Parkinson's disease.

Alda, 82, said he was diagnosed with the nervous system disorder three and a half years ago.

"I decided to let people know I have Parkinson's to encourage others to take action," he said in a statement on Twitter.

"My life is full. I act, I give talks, I do my podcast," he said. "I take boxing lessons 3 days a week, play singles tennis twice a week, and take a mild pill.

"And I'm not entering dementia," Alda said. "I'm no more demented than I was before."

"If you get a diagnosis, keep moving!"

In an appearance on "CBS This Morning," Alda said the only symptom he has experienced so far is twitching in his thumb.

Besides "M*A*S*H," the Emmy-winning Alda appeared on the popular TV political drama series "The West Wing" and was nominated for an Oscar for the movie "The Aviator."