The man who dared to boldly go where no one had gone before has revealed that he ca n't go as many places as he used to . `` I 'm doing OK , '' Leonard Nimoy tweeted Friday . `` Just ca n't walk distances . Love my life , family , friends and followers . '' Nimoy announced last week that he has been diagnosed with chronic obstructive pulmonary disease -- 30 years after having given up cigarettes . `` Not soon enough , '' tweeted the 82-year-old actor and director who played Spock , the half-human science officer aboard the Starship Enterprise from 1966 to 1969 on the TV series `` Star Trek '' and in movies during the decades since . `` I have COPD . Grandpa says , quit now ! ! ! LLAP . '' The last reference is to his signature phrase , `` Live long and prosper . '' Nimoy , who told an interviewer last year that he flunked chemistry in high school , may not have grasped the long-term risks associated with smoking , but his announcement is not surprising , said Dr. Richard Casaburi , a pulmonologist at Los Angeles Biomedical Research Institute in Torrance , California . Smoking could very well be responsible for the appearance of symptoms of COPD decades after quitting , because it is a progressive disease and lung function declines with age , said Casaburi , who is not involved with Nimoy 's treatment . COPD is the third-leading cause of death in the United States -- after heart disease and cancer -- and smoking is responsible for the vast majority of cases , he said . Some 12 million people in the United States have been diagnosed with the disease , and perhaps another 12 million have it , but do n't know , he said , adding that about 30 % of people who smoke will get clinically significant COPD . `` The mystery really is why everybody does n't get it . '' Initial symptoms can include cough , sputum production and shortness of breath , especially on exertion , which limits their activity . But medications typically can ease the symptoms , he said . `` It 's a disease of the older person , but the damage is started when they 're young . '' Though smoking rates have declined in the United States in recent years , COPD takes years to develop , so the incidence is rising , said the 66-year-old doctor . `` We 're now seeing the results of people my age who started smoking in the 1960s and now are reaping the consequences . '' He predicted the incidence will decline sharply over the next 20 to 30 years . More severe symptoms can require oxygen therapy and may lead to pneumonia and heart failure , said Dr. Norman Edelman , senior medical consultant to the American Lung Association . He praised Nimoy for his announcement and his admonition to stay away from tobacco . `` We 're delighted , '' Edelman said in a telephone interview . `` The more people speak out , the more ammunition we have to fight -- for not only smoking cessation but for research that will lead to better treatment of COPD . '' Funding has been limited by the belief among some that patients have only themselves to blame , a point of view that is unfair , he said . `` These people deserve the best treatment that we can provide , '' he said , adding that most smokers take up the habit before they are adults . But Nimoy 's illness has not interfered with his goal of living long and prospering . In 2010 , life expectancy at birth for someone born in the United States reached 78.7 , and Nimoy , who is 82 , appears to be continuing to prosper , too . `` Just taped my comments for Star Trek Fest to be aired on EPIX Feb. 16th , '' he wrote . `` Still enjoying my life . LLAP . ''
At 78.7 , Casaburi reveals he has lung disease -- Friday after quitting smoking . `` I 'm doing OK , '' he tweets Friday -- `` Just ca n't walk distances '' the American Lung Association is the nation 's third -leading cause of death . `` Still enjoying my life . LLAP . ''