Actor Alan Alda has announced he has Parkinson’s disease. The 82-year-old "M*A*S*H" star made the shocking announcement Tuesday on "CBS This Morning." "I have not said it in public until now, that I have been diagnosed with Parkinson's," Alda said. The disease affects the central nervous system and can often cause tremors. Alda said he received the news three years ago, but decided to reveal it now because he noticed his hand shaking in several recent television appearances.