At least one in four heavy, long-term smokers who do not quit will develop the deadly lung disease COPD, Danish scientists said on 18 October.
Chronic obstructive pulmonary disease includes chronic bronchitis and emphysema and is a leading cause of death world-wide. It begins with a cough and leads to fatigue shortness of breath and difficulty breathing as the lungs is destroyed.
The people monitored in the study-included smokers and non-smokers. The researchers checked their lung function at the start of the study and regularly over the 25-year period.
The results, which are published in the journal Thorax, showed that persistent smokers were six times more likely to develop COPD than non-smokers.
Deaths from COPD are increasing in most countries. The World Health Organisation (WHO) estimates it will become the third-biggest cause of death world-wide by 2020.