The actor spoke to Sky News about how he is coping with having Parkinson's disease on the 25th anniversary of the movie that made him famous.
Talking about how he deals with the disease, he said: 'I'm feeling OK. It's manageable. You know everybody gets their bag of hammers, this is just my bag of hammers, and I can handle it.'
The former Spin City star also admitted that he cannot believe how popular his Back To The Future films have been.
The movie trilogy is set to be re-released on DVD and Blu-Ray for the first time.
He said: 'There are people who know a lot more about the movie than I do. They know trivia and ask me about the space-time continuum and I say, 'I don't know, I was just in the movie!''