Spok was reportedly brought into 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 19th, according to TMZ.
The star - who is known for his stint on Star Trek - 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."
In case you're wondering about the 'LLAP', that's "Live Long and Prosper", of course.
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 said to be caused by cigarette smoke.
You know, just in case you were looking for further motivation to give up the cigs.
