“…“O” stands for obstruction —[the chest bellows action is deficient because of intrinsic factors such as injury to the bony thorax, respiratory muscles or diaphragm, radical chest surgery, open‐heart surgery, advanced tuberculosis, lung tumor, and chronic obstructive pulmonary lesions as in chronic bronchitis, emphysema, asthma or fibrosis. Extrinsic causes leading indirectly to obstruction are cerebrovascular accidents, central‐nervous‐system tumors or infection, drug intoxication, pulmonary edema, postsurgical tracheostomy, cardiopulmonary by‐pass, head and chest trauma, pulmonary embolism, severe kyphoscoliosis and arthritis (16). ] “B” stands for breathlessness (dyspnea).…”