Health A-Z

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What Is It?

Urethritis is an inflammation of the urethra, which is the tube that carries urine out of the body. Urethritis is usually caused by a sexually transmitted infection. Much less often, it is the result of an injury from an instrument such as a urinary catheter or exposure to an irritating chemical such as an antiseptic or a spermicide.

Doctors usually classify sexually transmitted (infectious) urethritis into two categories: gonococcal urethritis, caused by gonorrhea bacteria, and nongonococcal urethritis, caused by bacteria other than gonorrhea.

Gonococcal urethritis, commonly called clap, is caused by Neisseria gonorrhoeae bacteria. Gonorrhea infections are passed from person to person during sexual activity (vaginal, oral and anal intercourse).

Nongonococcal urethritis is caused by all sexually transmitted bacteria other than N. gonorrhea. The most frequent cause is Chlamydia trachomatis bacteria, which cause the sexually transmitted disease Chlamydia. Nongonococcal urethritis is the most common form of sexually transmitted infection in the United States. In addition to C. trachomatis,, other possible infectious causes of nongonococcal urethritis include Ureaplasma urealyticum, Mycoplasma genitalium and Trichomonas vaginalis.

Not all urethritis is caused by an infection or trauma. Reactive arthritis (formerly known as Reiter's syndrome) is an inflammatory disorder that usually has three features:

  • Painful and swollen joints, one or many

  • Conjunctivitis

  • Sterile urethritis

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From Health A-Z, Harvard Health Publications. Copyright 2007 by the President and Fellows of Harvard College. All rights reserved. Written permission is required to reproduce, in any manner, in whole or in part, the material contained herein. To make a reprint request, contact Harvard Health Publications. Used with permission of StayWell.

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