Urethritis

Overview

Urethritis is inflammation of the urethra, the tube that carries urine from the bladder out of the body. In men, it also transports semen during ejaculation. This condition is most commonly caused by sexually transmitted infections but can also result from chemical irritation or physical trauma.

Urethritis differs from urinary tract infections, which primarily affect the bladder. While both conditions cause painful urination, urethritis specifically involves the urethra and typically produces urethral discharge—a key distinguishing feature. Understanding this distinction helps ensure appropriate testing and treatment.

The condition is classified into two main types based on the causative organism. Gonococcal urethritis (GU) is caused by Neisseria gonorrhoeae and often produces more pronounced symptoms, including thick, purulent discharge. Non-gonococcal urethritis (NGU) encompasses all other infectious causes and is more common overall. Many cases of NGU present with milder symptoms, and approximately 20-30% remain unexplained despite thorough testing.

Symptoms

Symptoms vary considerably between individuals and between the sexes. Many infections cause no symptoms at all, which contributes to ongoing transmission among sexual partners.

In men, the most characteristic symptom is discharge from the penis, which may appear clear, white, or yellow-green depending on the causative organism. Dysuria—burning or pain during urination—is the second most common complaint. Men may also experience itching or irritation at the urethral opening, frequent urination, blood in urine or semen, pain during ejaculation, or swelling of the penile tip.

In women, urethritis often goes unrecognized because symptoms overlap with other conditions. Women may experience burning with urination, increased urinary frequency, vaginal discharge, pelvic discomfort, or pain during intercourse. These symptoms are frequently attributed to bacterial cystitis or vaginal infections, sometimes delaying correct diagnosis.

Symptom timing provides diagnostic clues. Gonorrhea typically produces symptoms within 2-5 days of exposure, while chlamydial infection may take 1-3 weeks to manifest. Some infections remain entirely asymptomatic, making routine screening essential for sexually active individuals.

Causes

Chlamydia trachomatis is the most common cause of NGU, responsible for 15-40% of cases. This intracellular bacterium often produces mild or absent symptoms, which allows infection to persist and spread unknowingly.

Mycoplasma genitalium accounts for 15-25% of NGU cases and has emerged as an increasingly important pathogen. This organism frequently causes persistent or recurrent urethritis when initial treatment fails.

Neisseria gonorrhoeae causes gonococcal urethritis and tends to produce more obvious symptoms than other organisms. Dual infection with both gonorrhea and chlamydia is common, which is why treatment regimens often address both simultaneously.

Trichomonas vaginalis, a protozoan parasite, causes trichomoniasis and can produce urethritis in both sexes. Herpes simplex virus occasionally causes urethral inflammation, particularly during primary outbreaks. Ureaplasma urealyticum and adenovirus represent less common infectious causes.

Non-infectious urethritis results from chemical irritation from soaps, spermicides, or lubricants. Physical trauma from urethral instrumentation, catheterization, or vigorous sexual activity can also trigger inflammation without infection.

Diagnosis

Clinical assessment begins with a detailed symptom history and sexual history, including information about recent partners, condom use, and prior STI diagnoses. Physical examination in men may reveal urethral discharge, meatal redness, or swelling.

Urethral swab testing provides rapid results for gonorrhea through Gram staining, which can identify the characteristic gram-negative intracellular diplococci. Swab specimens can also be sent for culture and nucleic acid amplification testing (NAAT), which offers the highest sensitivity for detecting both gonorrhea and chlamydia.

Urine testing has largely replaced urethral swabs for routine STI screening because patients find it more acceptable. First-void urine samples—the initial portion of the urine stream—contain the highest concentration of organisms and are used for NAAT testing.

Additional STI screening is recommended for anyone diagnosed with urethritis. This typically includes HIV testing, syphilis serology, and hepatitis B and C testing when indicated. Mycoplasma genitalium testing is increasingly available and should be considered for cases that fail initial treatment.

Treatment

Treatment often begins empirically before laboratory results return, particularly when symptoms strongly suggest infection.

For suspected gonococcal urethritis, the standard regimen includes ceftriaxone 500mg administered intramuscularly as a single dose to cover gonorrhea, plus doxycycline 100mg taken orally twice daily for seven days to cover possible chlamydial co-infection. This dual therapy approach reflects the high rate of co-infection between these organisms.

For non-gonococcal urethritis when gonorrhea has been excluded, doxycycline 100mg twice daily for seven days is the preferred treatment. Azithromycin 1g as a single dose was previously favored for convenience but is now less preferred due to increasing resistance, particularly among Mycoplasma genitalium strains.

Mycoplasma genitalium infection presents treatment challenges due to high resistance rates. When resistance testing is available, therapy should be guided by results. Otherwise, treatment typically involves doxycycline 100mg twice daily for seven days, followed by azithromycin 1g on day one then 500mg daily for an additional three days. Moxifloxacin may be required for resistant cases.

Trichomonas infection responds to metronidazole, given either as a single 2g dose or as 500mg twice daily for seven days.

Partner Management

All sexual partners from the past 60 days should be notified and offered testing and treatment. This prevents reinfection of the treated individual and breaks the chain of transmission. In some regions, expedited partner therapy allows providers to prescribe antibiotics for partners without requiring them to attend a clinical visit.

Sexual contact should be avoided until both the patient and their partner have completed treatment and any symptoms have resolved. Abstinence should continue for at least seven days after treatment begins.

Prevention

Consistent and correct condom use substantially reduces the risk of urethritis from sexually transmitted organisms. Limiting the number of sexual partners and maintaining mutual monogamy with a partner who has tested negative for STIs also reduces risk.

Regular STI screening is recommended for sexually active individuals, particularly those with new or multiple partners. Women under 25 should undergo annual chlamydia screening regardless of symptoms. Men who have sex with men should be tested at least annually, and more frequently if they have multiple partners.

Avoiding potential irritants such as perfumed soaps, harsh cleansers, and spermicides near the genital area helps prevent non-infectious urethritis.

When to See a Doctor

Seek medical evaluation promptly for any urethral discharge, burning or pain during urination, or notification that a sexual partner has been diagnosed with an STI. These symptoms warrant testing even if they seem mild.

Return for follow-up if symptoms persist beyond the treatment period or recur after initial improvement. Persistent urethritis may indicate treatment failure, reinfection from an untreated partner, or infection with a resistant organism requiring alternative therapy.

Untreated urethritis carries serious risks. In men, infection can spread to cause epididymitis or prostatitis, potentially affecting fertility. Urethral stricture from repeated inflammation can narrow the urethra and cause long-term voiding difficulties. In women, ascending infection can lead to pelvic inflammatory disease, chronic pelvic pain, infertility, or increased risk of ectopic pregnancy.

Complete all prescribed antibiotics even if symptoms resolve before the course ends. Attend recommended follow-up appointments, particularly if symptoms persist, and discuss regular STI screening with your healthcare provider if you remain sexually active with new or multiple partners.