Chlamydia often causes no symptoms at all. Roughly 75% of women and 50% of men with chlamydia never notice anything wrong, which is why it’s the most commonly reported bacterial sexually transmitted infection in the United States. When symptoms do appear, they typically show up one to three weeks after exposure, though some people don’t develop signs until much later.
Symptoms in Women
When chlamydia does produce symptoms in women, the most common signs are abnormal vaginal discharge and a burning sensation when urinating. The discharge may have an unusual smell or color compared to what’s normal for you. Some women also experience bleeding between periods, which is easy to dismiss as spotting but can signal infection of the cervix.
Pain during sex and lower abdominal pain are also possible, particularly if the infection has started to spread beyond the cervix. These symptoms overlap with many other conditions, from urinary tract infections to yeast infections, so they’re easy to misattribute. The key difference is that chlamydia won’t resolve on its own and requires antibiotic treatment.
Symptoms in Men
Men who develop symptoms most commonly notice a discharge from the penis that looks clear, watery, or slightly mucus-like. This is different from the thicker, yellowish discharge more typical of gonorrhea, though the two infections can occur together. A burning or stinging sensation during urination is the other hallmark symptom.
Some men also experience burning or itching around the opening of the penis. Less commonly, pain or swelling in one or both testicles can develop, which usually signals that the infection has spread to the epididymis, the coiled tube behind each testicle that stores and carries sperm. This progression typically causes one-sided testicular pain and tenderness, sometimes with visible swelling.
Rectal and Throat Infections
Chlamydia can infect the rectum through receptive anal sex, or occasionally by spreading from a vaginal infection. Rectal chlamydia may cause pain, discharge, or bleeding from the rectum, but it’s frequently silent. Throat infections from oral sex are also possible and almost always produce no symptoms. Because these infections don’t announce themselves, testing at the actual site of exposure matters. A standard urine test won’t catch a rectal or throat infection.
Why No Symptoms Doesn’t Mean No Problem
The fact that most chlamydia infections are silent is precisely what makes them dangerous. In women, untreated chlamydia can climb from the cervix into the uterus and fallopian tubes, causing pelvic inflammatory disease (PID). PID can lead to chronic pelvic and abdominal pain, scarring of the reproductive tract, and difficulty getting pregnant. Some women don’t realize they had chlamydia until they’re evaluated for infertility years later.
In men, the main complication is epididymitis, an inflammation of the tube behind the testicle. It causes pain, swelling, and tenderness that usually affects one side. Acute epididymitis from chlamydia lasts less than six weeks with treatment, but ignoring it can lead to lasting discomfort. Interestingly, the urethral infection that triggers epididymitis is itself frequently asymptomatic, meaning a man can develop a painful complication from an infection he never knew he had.
How Testing Works
Because symptoms are unreliable, testing is the only way to know your status. The standard test is a nucleic acid amplification test (NAAT), which detects the genetic material of the bacteria. It’s the most accurate test available and works whether or not you have symptoms. For most people, it requires only a urine sample or a swab. If you’ve had oral or anal exposure, a swab at that specific site is necessary for accurate results.
Who Should Get Tested Routinely
CDC screening guidelines recommend annual chlamydia testing for all sexually active women under 25, regardless of symptoms or perceived risk. Women 25 and older should be tested annually if they have a new partner, more than one partner, a partner who has other partners, or inconsistent condom use outside a mutually monogamous relationship.
For men who have sex with men, the CDC recommends testing at least once a year at all sites of contact (urethra, rectum), with more frequent screening every three to six months for those on PrEP, living with HIV, or with multiple partners. There’s no blanket recommendation for heterosexual men at low risk, though screening is encouraged in high-prevalence settings like STI clinics or correctional facilities.
Transgender and gender diverse individuals should follow the guidelines that match their anatomy. Anyone with a cervix who is under 25 and sexually active qualifies for routine annual screening. All people living with HIV should be screened at their first evaluation and at least annually after that.
Chlamydia is curable with a short course of antibiotics, and early treatment prevents every complication listed above. The challenge is catching an infection that, more often than not, gives you no reason to suspect it’s there.