Research in the works of the Byzantine medical authors brought to light significant information concerning disorders of the sperm as causes of infertility. The eminent Byzantine physicians give detailed accounts about the anatomy of the genitals, the creation of the sperm and its disorders as regards its quantity, quality, appearance, consistency, colour, ejaculation etc. According to those authors, the disorders of the sperm are due to, dietetic reasons (a list of foods and drugs influencing the production of sperm is referred to by many Byzantine physicians); constitution and age of the patient; obesity; diseases, such as "gonorrhea" (involuntary loss of sperm), oneirogmus, stenosis of the spermiducts, hypospadias and atrophy of the genitals; iatrogenic reasons (traumatic cutting off of the spermiducts during a lithotomy); castration. These concepts were based on the works of the ancient Greek physicians of the Hippocratic, Hellenistic and Roman eras. However, such ideas, enriched by the personal experience of the Byzantine doctors, were transmitted to and influenced Islamic and European medicine and thus the rest of the world.