Star Trek's Leonard Nimoy was reportedly rushed to hospital with "severe chest pain" last week.
The 83-year-old actor - who suffers from chronic obstructive pulmonary disease - was taken to UCLA Medical Center in Los Angeles via an ambulance after complaining of discomfort in his chest on February 19, according to gossip site TMZ.com.
The star - who is known for his portrayal of Commander Spock - has been in-and-out of hospital on numerous occasions in the past few months and was spotted last year in New York in a wheelchair attached to a breathing apparatus.
Leonard took to Twitter last February to announce that he'd been diagnosed with the condition, despite giving up smoking over 30 years ago, and encouraged people to look after their health.
He wrote at the time: : ''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 [live long and prosper] (sic)."
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.