 What are the differential effects of beta-blockers on lung and heart function during exercise in chronic obstructive pulmonary disease COPD? COPD is a major cause of illness and death. Not only do these individuals suffer from lung disease, but COPD often leads to other illnesses, particularly heart disease. Beta-blockers very successfully treat heart disease. It is therefore logical that one would want to use this treatment in COPD patients with heart disease too. However, there has always been concern that beta-blockers could cause significant problems in COPD by worsening lung function, as these can have the opposite effect to inhalers used to treat COPD that open up airways. Pointedly, there is increasing evidence that despite this problem, COPD patients who have been prescribed beta-blockers have been shown to gain benefit particularly in terms of preventing death. 