Pulmonology is studied a branch of internal medicine, and is related to intensive care medicine. Pulmonology often affect managing patients who need life support and mechanical ventilation. Pulmonologists are specially trained in diseases and circumstances of the chest, notably pneumonia, asthma, tuberculosis, emphysema, and complicated chest infections. [2]One of the first major discoveries relevant to the field of pulmonology was the discovery of pulmonary circulation. Originally, it was thought that blood reaching the right side of the heart travelled through small 'pores' in the septum into the left side to be oxygenated, as theorized by Galen; however, the discovery of pulmonary circulation belie this theory, which had previously been accepted since the second century.