Alan Alda publicly revealed a very personal truth on CBS This Morning July 31.

The much beloved M*A*S*H actor, science advocate and writer was diagnosed with Parkinson's Disease three and a half years ago – he has only now decided to make that news public to fans because he does not want those afflicted by the disease to be "immobilized" from fear.

Alda further explained that during TV appearances promoting his new podcast (Clear+Vivd with Alan Alda), that "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."

Indeed, the tweet below from Alda shows a lot about where he is.

Alda, who has hosted PBS's Scientific American Frontiers for 13 years, says he looks at Parkinson's as if it were a puzzle, every day deducing "what do I have to adapt to, to carry on a normal life."

The full CBS This Morning interview is embedded in the 3 tweets below.