Mainland doctors are urging people with persistent coughs, shortness of breath and other lung problems to seek medical attention soon in an effort to reduce the country's disproportionate number of deaths from chronic obstructive pulmonary disease, or COPD.
The warning came this week as the international health community marked World COPD Day to raise awareness of the disease, which the World Health Organisation says is the fourth leading cause of death worldwide.
China accounts for more than 43 million of the estimated 210 million people globally who suffer from the disease, which is caused by smoking and pollution and includes emphysema and chronic bronchitis.
While that number is roughly proportionate to China's share of the global population - a fifth - it accounts for more than a third of those who die from COPD.
Health authorities say that is because many Chinese suffering from the disease wait too long to see a doctor. The most recent national COPD survey, in 2000 by leading respiratory health expert Dr Zhong Nanshan , estimated that just nearly two-thirds of cases go undiagnosed.
The diagnosis rate remains low more than decade later due to poor awareness among patients and doctors alike, said Dr Bai Chunxue chairman of Shanghai Respiratory Research Institute. Bai said people must take common symptoms, like persistent coughing and excessive mucous, more seriously.
"People affected by COPD, especially chain smokers, think that coughing a lot and much sputum is not a big deal and that it is just a normal thing for smokers," Bai said. "They won't come to hospitals to check their lungs unless the disease is so serious that it affects their life.
"For example, if they feel short of breath when doing simple daily activities, such as eating and walking," he said.
Dr Chen Rongchang , deputy director of Guangzhou Institute of Respiratory Disease, said most patients ignored COPD because its symptoms were mild at the initial stage and people generally did not understand that it was irreversible. It becomes progressively more serious over time if left untreated. Moreover, many mainland doctors lack sufficient knowledge of COPD and fail to test patients' lung function in physical examinations.
WHO forecasts COPD will overtake lower respiratory infections to become the world's third leading cause of death by 2030, after heart disease and stroke.
One Shanghai man who attended a health education session at Shanghai Zhongshan Hospital with his wife on Tuesday said he had no idea about the disease before being diagnosed with COPD a year ago.
The 58-year-old man, who declined to give his name, said he used to smoke heavily and cough intensely. Whenever his cough got too bad, he took antibiotics, which seemed to relieve the symptoms.
Chen said the later the diagnosis, the more difficult it was to treat the disease. "In the late stage, patients need to have a big bunch of drugs, which nonetheless makes the situation improve slightly," he said.
The 2000 survey found that 8.2 per cent of mainlanders over the age of 40 suffer from COPD. Some 12.4 per cent of men have the disease, more than double the rate among women.