Chlamydia is a sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis. This infection is widespread because many people who contract it do not experience symptoms. While an unusual urine odor often leads people to suspect an STI, this symptom is not a definitive indicator of Chlamydia.
The Direct Answer: Urine Odor and Chlamydia
Chlamydia infection itself does not typically cause the urine to have a strong or specific smell. The bacteria primarily infects the urethra and the reproductive tracts, and the urine produced by the kidneys is generally sterile and clear of the infection’s direct odor-causing compounds. Any odor noticed is usually an indirect result of the infection, rather than a change in the urine’s chemical composition.
If an unpleasant odor is present, it is most often due to secondary factors, such as inflammation of the urethra, known as urethritis. The smell can result from abnormal discharge—which may contain pus or mucus—mixing with the urine as it leaves the body. This discharge may have its own strong or unpleasant odor that gets transferred to the urine sample. The presence of pus in the urine (pyuria) is one sign that a urogenital infection like Chlamydia is causing inflammation.
Primary Symptoms of Chlamydia Infection
Since relying on urine odor is unreliable, it is important to recognize the common clinical signs of a Chlamydia infection. Up to 75% of women and 50% of men who contract it may remain completely asymptomatic, making regular screening important. When symptoms do appear, they can manifest differently in men and women, usually appearing one to three weeks after exposure.
Symptoms in Women
For women, Chlamydia can cause a noticeable change in vaginal discharge, which might be white, yellow, or gray and may be accompanied by a foul odor. Other symptoms include pain or a burning sensation when urinating (dysuria), and pain during sexual intercourse. The infection can also cause lower abdominal pain or bleeding between menstrual periods.
Symptoms in Men
In men, the infection most commonly presents as an inflammation of the urethra, leading to dysuria and a discharge from the tip of the penis. This penile discharge is typically clear, cloudy, or mucus-like. Some men may experience pain, tenderness, or swelling in one or both testicles, a condition called epididymitis, if the infection spreads. Untreated infection can lead to serious complications in both sexes, including pelvic inflammatory disease (PID) in women.
Differentiating Other Causes of Urinary Odor
Concerns about unusual urine odor are often linked to factors entirely unrelated to sexually transmitted infections. One of the most common causes of a strong ammonia-like smell is dehydration, which causes urine to become highly concentrated. When there is less water to dilute the waste products, the smell of ammonia naturally becomes more noticeable.
A more concerning, but still non-STI-related, cause is a urinary tract infection (UTI), which often results in urine with a strong, foul, or sometimes slightly sweet odor. Accompanying symptoms usually include a frequent and intense urge to urinate, along with a burning sensation during urination. Certain foods, such as asparagus, and some medications, including certain antibiotics and B vitamins, can temporarily alter the scent of urine.
Necessary Steps for Diagnosis and Treatment
If there is any suspicion of Chlamydia exposure or if any symptoms are present, medical testing is required. Diagnosis is most commonly performed using a nucleic acid amplification test (NAAT). This test can analyze a first-catch urine sample or a swab taken from the affected area, such as the cervix, urethra, or rectum. NAAT testing is simple and highly accurate.
Treatment for an uncomplicated Chlamydia infection is straightforward and involves a course of antibiotics. The most common regimens include a single dose of azithromycin or a seven-day course of doxycycline. Patients are advised to abstain from sexual activity for seven days after the single-dose treatment or until the completion of the seven-day course to ensure the infection is cleared and to prevent transmission. It is also necessary to inform all recent sexual partners so they can be tested and treated, which helps prevent reinfection and further spread.