Chlamydia: Symptoms, Testing, Treatment and Complications

Chlamydia is a common sexually transmitted infection (STI), caused by the bacterium Chlamydia trachomatis. Anyone can get it. It often causes no symptoms at all, so many people do not know they are infected — and although antibiotics cure it, an infection left untreated can cause serious health problems.

How it spreads

Chlamydia passes between people during oral, vaginal or anal sex with someone who has it. A mother can also pass it to her baby during childbirth. Having had chlamydia and been treated does not protect anyone: unprotected sex with an infected partner can bring it back.

It is more common in young people, especially young women. Not using a condom every time, or having multiple partners, raises the chance of infection.

Symptoms

Most people with chlamydia have no symptoms, yet they can still pass it on. When symptoms do come, they may not appear until several weeks after sex with an infected partner.

In women:

• unusual vaginal discharge, which may smell strongly;
• a burning feeling when urinating; and
• if the infection spreads, pain in the lower abdomen, pain during sex, nausea and fever.

In men:

• discharge from the penis;
• a burning feeling when urinating; and
• less often, pain and swelling in one or both testicles.

In anyone, chlamydia in the rectum can cause rectal pain, discharge and bleeding.

Testing

Lab tests diagnose chlamydia, usually from a urine sample or from a swab of the vagina that a provider takes or asks the patient to take.

It is worth being tested whenever there are symptoms or a partner has an STI, and at the first prenatal visit during pregnancy. People at higher risk should be checked every year:

• sexually active women aged 25 and younger;
• older women with a new partner, several partners, or a partner who has an STI; and
• men who have sex with men.

What it can lead to

In women, untreated chlamydia can travel to the uterus and fallopian tubes and cause pelvic inflammatory disease (PID). PID can damage the reproductive system permanently, leading to long-term pelvic pain, infertility and ectopic pregnancy. Women who have had chlamydia more than once face a higher risk of these serious complications.

Men often have no lasting problems, but the infection sometimes reaches the epididymis, the tube that carries sperm, causing pain, fever and, rarely, infertility.

Both men and women can develop reactive arthritis, a form of arthritis set off as a reaction to an infection elsewhere in the body. Untreated chlamydia may also make it easier to catch or pass on HIV.

Babies born to infected mothers can get eye infections and pneumonia from chlamydia, and the infection may make an early birth more likely.

Treatment

Antibiotics cure chlamydia — either a single dose, or a dose every day for 7 days. It matters to take all of the medicine prescribed. Antibiotics cannot, though, undo any permanent damage the infection has already done.

To avoid passing it on, wait before having sex again: for 7 days after a single dose, or until the last dose of a 7-day course. Repeat infections are common, so another test about three months after treatment is recommended.

Prevention

The only certain way to avoid chlamydia is not to have vaginal, anal or oral sex. Using latex condoms correctly cuts the risk of catching or spreading it a great deal, though not entirely. For anyone allergic to latex, polyurethane condoms are an alternative.

Sources

Based on "Chlamydia Infections," MedlinePlus, National Library of Medicine, with information from the Centers for Disease Control and Prevention; a work of the United States government in the public domain.