The terms are interchangeable in clinical practice. A pulmonologist, chest physician, respiratory physician, and respiratory disease specialist all refer to the same subspecialty of medicine — a doctor who has completed specialist training in the diagnosis and treatment of conditions affecting the lungs and respiratory system. In India, the formal postgraduate qualifications are MD Respiratory Medicine, DNB Respiratory Medicine, or MD Chest Medicine. At Pulmovista Clinics, I hold specialist qualifications in respiratory medicine and have 13+ years of subspecialty clinical experience in Delhi.