Chlamydia often causes no symptoms at all. Roughly 75% of women and 50% of men with the infection never notice anything wrong, which is why it spreads so easily and why routine screening matters. When symptoms do appear, they typically show up one to three weeks after exposure, though some people don’t notice anything for much longer.
Symptoms in Women
The most common signs in women are abnormal vaginal discharge and a burning sensation when urinating. The discharge may look different from what’s normal for you, sometimes with an unusual color or smell. Some women also notice bleeding between periods or after sex.
These early symptoms are easy to brush off or mistake for a urinary tract infection or yeast infection. Because they tend to be mild, many women don’t seek testing until the infection has been present for weeks or months. That delay is part of what makes chlamydia dangerous: the longer it goes untreated, the more likely it is to cause serious problems deeper in the reproductive tract.
Symptoms in Men
Men are somewhat more likely to notice symptoms than women, though half still won’t. The most recognizable sign is discharge from the penis, which can appear white, cloudy, or watery. Burning or pain during urination is also common.
Other symptoms include redness, swelling, or itching at the tip of the penis, and pain or swelling in one or both testicles. Testicular symptoms suggest the infection has spread to the epididymis, the coiled tube behind each testicle that stores sperm. Pain during ejaculation can also occur.
Rectal and Throat Infections
Chlamydia doesn’t only infect the genitals. It can also establish itself in the rectum or throat depending on the type of sexual contact involved. Rectal chlamydia may cause discharge, pain, or bleeding from the rectum. Throat infections from oral sex are usually silent but can occasionally cause a sore throat or cough.
These infections are easy to miss because standard urine tests won’t detect them. A swab of the specific site is needed. The CDC recommends annual rectal screening for men who have receptive anal sex, and rectal testing can also be considered for women based on their sexual history.
When Testing Is Accurate
If you think you’ve been exposed, timing matters. A chlamydia test taken too soon after exposure can come back negative even if you’re infected. Waiting at least one week after exposure catches most infections. Waiting two weeks catches nearly all of them. Testing can be done with a urine sample or a swab of the vagina, rectum, or throat depending on the site of possible exposure.
Because so many infections produce no symptoms, the CDC recommends annual screening for all sexually active women under 25, and for older women with risk factors like a new partner or multiple partners. Routine screening for young men isn’t universally recommended, but it’s encouraged in high-prevalence settings like STI clinics and correctional facilities.
How Chlamydia Differs From Gonorrhea
Chlamydia and gonorrhea share many of the same symptoms: burning during urination, unusual discharge, and rectal discomfort. You can’t reliably tell them apart based on how you feel, and it’s possible to have both at the same time. Testing is the only way to know which infection you’re dealing with.
There are a few tendencies that differ. Gonorrhea in men tends to produce more obvious, heavier discharge and more severe symptoms overall. In women, gonorrhea is more likely to cause heavier periods and pain during sex. Chlamydia, by contrast, is more likely to be completely silent, especially early on. But these are patterns, not rules. Either infection can look like the other, or like nothing at all.
What Happens If It Goes Untreated
Left alone, chlamydia can move beyond the initial site of infection and cause significant damage. In women, the biggest concern is pelvic inflammatory disease (PID), an infection of the uterus and fallopian tubes. PID causes abdominal and pelvic pain, fever, nausea, and vaginal bleeding. It can also scar the fallopian tubes, leading to infertility or ectopic pregnancy, where a fertilized egg implants outside the uterus. Ectopic pregnancies are medical emergencies.
In men, untreated chlamydia can cause epididymitis, a painful infection and swelling in the testicles. In rare cases, this can also lead to infertility. Both men and women can develop reactive arthritis, a condition involving swollen, painful joints and eye inflammation, as an immune response to the infection.
A less common but more aggressive form of chlamydia, called LGV, can cause genital ulcers, swollen lymph nodes, and severe inflammation of the rectal area with symptoms like abdominal cramps, diarrhea, constipation, and fever. This form is more frequently seen in men who have sex with men.
Who Should Get Tested
Given how frequently chlamydia produces no symptoms, testing is the only reliable way to catch it. You should consider testing if you’re sexually active and fall into any of these groups:
- Women under 25: annual screening is recommended regardless of symptoms
- Women 25 and older: if you have a new partner, multiple partners, or a partner who has an STI
- Men who have sex with men: annual screening, including rectal testing
- Anyone with a new sexual partner: testing before or shortly after starting a sexual relationship reduces the chance of unknowingly passing infections
Chlamydia is curable with antibiotics, and treatment is straightforward when the infection is caught early. The complications described above are almost entirely preventable with timely testing and treatment. If you test positive, any recent sexual partners should be notified and tested as well, since reinfection from an untreated partner is common.