He gave up smoking 30 years ago. Lesson to be learned there, kiddies... And, yes, I know at 82 he's had good innings, but you're forgetting he's part Vulcan.
The actor - famous for playing Mister Spock in the original Star Trek TV series and movies - has developed obstructive pulmonary disease, despite quitting smoking 30 years ago, and has urged his fans to ditch the cigarettes before it's too late.
He Tweeted: "I quit smoking 30 yrs ago. Not soon enough. I have COPD. Grandpa says, quit now!! LLAP... Smokers, please understand. If you quit after you're diagnosed with lung damage it's too late. Grandpa says learn my lesson. Quit now. LLAP... I'm doing OK. Just can't walk distances. Love my life, family, friends and followers. LLAP (sic)" That's short for 'Live Long and Prosper', obvs.
Nimoy - who had a cameo as Spock Prime in 2013 film Star Trek Into Darkness - was spotted last month in New York City leaving the hospital in a wheelchair, while attached to a breathing apparatus.
Park your lunch plans for a minute, 'cause here comes the science bit: Chronic obstructive pulmonary disease (COPD) is a term used for a number of illnesses affecting the lungs, including emphysema and chronic bronchitis, which affects millions of people around the world. The disease damages the air sacs and passages into the lungs, which can then make breathing difficult, and the majority of cases are believed to be caused by cigarette smoke.
Now, go forth and enjoy your burrito. But if you're having a smoke after, spare a thought for your little sacs.