[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Lower urinary tract and male genital system](https://durgical.com/en/general-pathology/areas/urinary-male/) › Diseases of the urethra

# Diseases of the urethra

- Lesion

The urethra is inflamed mainly by sexually transmitted infections; caruncles and rare carcinomas complete its pathology.

Updated Nov 12, 2026

## Key points

- Gonococcal urethritis: purulent discharge, Gram-negative intracellular diplococci.
- Non-gonococcal: Chlamydia most common; often fewer symptoms; frequently both infections coexist.
- Reactive arthritis: urethritis, conjunctivitis and arthritis after Chlamydia or enteric infection; HLA-B27.
- Caruncle: polypoid granulation tissue with inflammation covered by urothelium or squamous epithelium.
- Carcinoma: distal tumours are squamous (HPV in some), proximal ones urothelial.

## What it is

Urethritis is classified as gonococcal (Neisseria gonorrhoeae) or non-gonococcal, mostly Chlamydia trachomatis, with Mycoplasma genitalium and Trichomonas vaginalis less often. Urethritis can accompany reactive arthritis with conjunctivitis. The urethral caruncle is a small, painful, red inflammatory polyp at the meatus of older women. Urethral carcinoma is rare; it is squamous in the distal urethra and urothelial in the proximal part, and adenocarcinoma can arise in women.

## Structure

- Acute urethritis: neutrophils in the mucosa and periurethral glands; chronic forms cause strictures.
- Caruncle: friable red mass of vascular, inflamed stroma at the meatus.
- Carcinoma: infiltrative mass, often advanced at diagnosis.

## Clinical notes

- Dysuria and urethral discharge in a sexually active man: test for both gonorrhea and chlamydia.
- Untreated urethritis can spread to the epididymis and prostate.

## Memory aid

Pus with diplococci is gonorrhea; thinner discharge, think chlamydia; joints and eyes too, think reactive arthritis.

## Test yourself

Think of the answer, then tap the question to see it.

## What is the commonest cause of non-gonococcal urethritis?

Chlamydia trachomatis.

## What is a urethral caruncle?

A small, painful inflammatory polyp of the urethral meatus, usually in older women.

## What triad defines reactive arthritis?

Arthritis, urethritis and conjunctivitis, following a genitourinary or enteric infection.

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## Connections

## Related 3

- [Epididymitis, orchitis and prostatitis](https://durgical.com/en/general-pathology/epididymitis-orchitis-and-prostatitis/)
- [Cystitis and bladder metaplasias](https://durgical.com/en/general-pathology/cystitis-and-bladder-metaplasias/)
- [Penile tumours](https://durgical.com/en/general-pathology/penile-tumours/)

## Related conditions 4

- [Gonorrhoea](https://durgical.com/en/conditions/gonorrhoea/)
- [Chlamydia infection](https://durgical.com/en/conditions/chlamydia-infection/)
- [Reactive arthritis](https://durgical.com/en/conditions/reactive-arthritis/)
- [Trichomoniasis](https://durgical.com/en/conditions/trichomoniasis/)

## Microorganisms 3

- [Neisseria gonorrhoeae](https://durgical.com/en/microbiology/neisseria-gonorrhoeae/)
- [Chlamydia trachomatis](https://durgical.com/en/microbiology/chlamydia-trachomatis/)
- [Trichomonas vaginalis](https://durgical.com/en/microbiology/trichomonas-vaginalis/)

[← All of general pathology](https://durgical.com/en/general-pathology/)

Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Gonorrhea](https://medlineplus.gov/gonorrhea.html) (MedlinePlus, US National Library of Medicine, 2025); [Urethral Cancer Treatment (PDQ®)–Patient Version](https://www.cancer.gov/types/urethral/patient/urethral-treatment-pdq) (National Cancer Institute, 2025).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/general-pathology/diseases-of-the-urethra/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/diseases-of-the-urethra/