Viagra may ease blood pressure in the lungs of people with chronic obstructive pulmonary disease (COPD).

        That’s according to a small Dutch study. COPD is the no.4 cause of death in the U.S. and worldwide, according to the National Heart and Lung and Blood Institute.

        COPD is a lung disease in which breathing is difficult. It’s usually caused by smoking cigarettes, but it can also be caused by other lung irritants.

        The disease develops slowly and may take years to show symptoms, which include: cough, sputum production, shortness of breath (especially with exercise), wheezing, and chest tightness.

        Those symptoms may or may not indicate COPD. The Viagra study included 12 COPD patients, half of whom had high blood pressure in the pulmonary artery, which brings blood to the lungs. The development of pulmonary hypertension is a complication of COPD, but not everyone with COPD will develop it.

        They tracked the patients pulmonary artery blood pressure before and after taking Viagra. Why Viagra? It relaxes (dilates) blood vessels, lowering blood pressure and helping blood to flow. First, the patients rested. Then they pedaled a stationary bike for three minutes at a mild pace. As expected. Pulmonary artery pressure was higher during exercise, since the lungs were working harder. Next, the patients took a Viagra pill, waited 45 minutes, and repeated the rest and exercise tests. Their pulmonary artery blood pressure during exercise was lower after taking Viagra. These data suggest that during daily activities some COPD patients may benefit from drugs that dilate blood vessels, the researchers write.