RT Journal Article SR Electronic T1 An unusual case of persisting hypoxia in a patient with a thrombolysed pulmonary embolism JF Clinical Medicine JO Clin Med FD Royal College of Physicians SP 593 OP 596 DO 10.7861/clinmed.2020-0753 VO 20 IS 6 A1 Sanjoy Ray A1 Shakeel A Qureshi A1 Natalie Stolagiewicz A1 Lydia Sturridge A1 Sitara Khan YR 2020 UL http://www.rcpjournals.org/content/20/6/593.abstract AB Exertional breathlessness and hypoxia are common presenting complaints in acute medicine. We describe a case where the patient continued to have persistent hypoxia even after the primary cause (pulmonary embolism) was diagnosed and treated. The hypoxia persisted as an enigma, its cause remaining elusive till diagnosed. Standard first-line investigations would not have reached the underlying diagnosis in this case and, as such, it demonstrates the keen clinical sense and complex investigative strategy required to solve the puzzle.