Pulmonary medicine is the branch of medicine that focuses on the prevention, diagnosis, and treatment of conditions that affect the respiratory system. This includes diseases such as asthma, chronic obstructive pulmonary disease (COPD), pneumonia, tuberculosis, and lung cancer. Pulmonary medicine also encompasses the evaluation and management of sleep disorders, such as sleep apnea. Pulmonologists, who are physicians specializing in pulmonary medicine, use various diagnostic tests and treatment modalities, such as medications, inhalers, oxygen therapy, and pulmonary rehabilitation, to help patients improve their respiratory health and quality of life.