title: Into thin air: medical problems at new heights.
mesh_terms: D000337:Aerospace Medicine; D000531:Altitude; D000532:Altitude Sickness / Q000209:etiology / Q000517:prevention & control; D001469:Barotrauma / Q000209:etiology; D006801:Humans; D008297:Male; D010809:Physical Fitness; D010879:Piperazines / Q000627:therapeutic use; D011687:Purines / Q000627:therapeutic use; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000627:therapeutic use; D014665:Vasodilator Agents / Q000627:therapeutic use
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate