Wheeziness and coughing are common smoking side-effects, but nearly three-quarters of smokers have never had their lungs checked for more serious diseases, according to a survey.
COPD can cause breathlessness, persistent coughing, chest infections and pain, excess phlegm and a wheezy chest.
The British Lung Foundation found 21% of people had some of these symptoms, with 19% feeling breathless when walking up a slight hill. A further 8% had to stop for a breather while walking on a flat surface.
Of those surveyed, 73% had not had a lung function test to check for COPD. About 900,000 people in the UK are diagnosed with the disease, but an estimated 3.7 million are unaware they have the condition.
The British Lung Foundation encourages smokers to have a painless 10-minute lung function test, which involves blowing into a tube.
Dame Helena Shovelton, British Lung Foundation chief executive, said: “Symptoms such as breathlessness and a persistent cough are often ignored by smokers or ex-smokers as signs of getting older, but they could be symptoms of COPD.
“COPD is a chronic, irreversible disease that can leave individuals unable to perform simple everyday tasks and dependent on oxygen if it is left untreated.”