In medicine, pulmonology (aka pneumology) is the specialty that deals with diseases of the lungs and the respiratory tract. It is called chest medicine and respiratory medicine in some countries and areas. Pulmonology is generally considered a branch of internal medicine, although it is closely related to intensive care medicine when dealing with patients requiring mechanical ventilation. Surgery of the respiratory tract is generally performed by specialists in cardiothoracic surgery (or thoracic surgery). Chest medicine is not a specialty in itself but is an inclusive term which pertains to the treatment of diseases of the chest and contains the fields of pulmonology, thoracic surgery, and intensive care medicine. Pulmonology is concerned with the diagnosis and treatment of lung diseases, as well as secondary prevention (tuberculosis). Physicians specializing in this area are called pulmonologists.