Pursed lip breathing is beneficial for people with chronic lung diseases, particularly COPD. It can help strengthen the lungs and make them more efficient, suggests the findings from a new research. People with these conditions typically feel breathless, cough, mucus production while coughing, and wheeze have a tight feeling in their chest. Pursed lip breathing can help the lungs work better, and it may ease these symptoms. For people with healthy lungs, the diaphragm plays a role in the mechanics of breathing, contracting when a person breathes in to draw air into the lungs. The  technique involves breathing in through the nose and breathing out slowly through the mouth. Repeated pursed lip breathing should slow breathing and empty the lungs. Pursed lip breathing can form part of a pulmonary rehabilitation program.