By: Rabie E. Abdel-Halim and Salah R. Elfaqih, Wed 06 May, 2009 This is a study and translation of the section on pericarditis in Kitab al-taysir fi al-mudawat wa-'l-tadbir (Book of Simplification Concerning Therapeutics and Diet) written by the Muslim physician Ibn Zuhr (Avenzoar) who lived and practiced in Al-Andalus between 1091-1162 CE. Ibn Zuhr described the serous type of pericarditis as well as the pathological findings in fibrinous pericarditis. His description of the latter may also fit with the picture of chronic fibrous pericarditis. He also described acute purulent pericarditis and involvement of the pericardium in cases of acute carditis with hectic fever. Ibn Zuhr's description of the pericardial effusion in serous pericarditis as "looking like urine" indicates that he must have seen a sample of the fluid obtained either by pericardiocentesis or during a post-mortem examination. However, his description of "solid substances accumulating on the inside of the heart's covering looking like layers upon layers of membranes" could not have been made possible without post-mortem dissection.