The term urethritis refers to inflammation of the urethra, which can be attributed both to infectious and noninfectious processes. The urethral canal essentially represents the first site of the body to be exposed to a variety of sexually transmitted pathogens, and the interaction of these pathogens with the epithelial cells of the urethra gives rise to the syndrome's symptoms.
Dysuria refers to the experience of pain, burning sensation or discomfort in urination and is a subjective symptom related to varying pathology of the urinary tract. Urethra being the terminal pathway of urine flow, its inflammation most often accounts the for experience of dysuria.
Traditionally urethritis has been divided into gonococcal urethritis (GU) and nongonococcal urethritis (NGU). Neisserria gonorrhoeae as a cause of urethritis has been recognized since ancient years, and in fact its name represents a description, in Greek, of the syndrome's symptoms as defined by Galen: “gono” referring to semen, which was supposed to be the main constituent of the urethral discharge, and “rrhea” a term for flow. Descriptions of urethritis exist in the Old Testament, in the Book of Leviticus, in ancient Chinese documents, and in the Hippocratic Corpus.
Nongonococcal urethritis has been often considered synonymous to Chlamydia trachomatis infection, although a continuously increasing number of pathogens are also implicated (Table 58.1). Chlamydia trachomatis is generally thought of as the commonest cause of NGU, especially in younger patients, although some studies suggest that Ureaplasma urealyticum, biovar 2, may be a more prevalent cause of infection.