Chlamydia infection: symptoms, treatment and causes


A chlamydia infection is one of the most common sexually transmitted infections. Its symptoms differ between men and women, but it can also be asymptomatic. We explain what complications can result and what kind of treatment helps.

What are chlamydia?

Chlamydia are bacteria. There are different types of chlamydia that lead to different diseases in humans. However, those who “have chlamydia” usually mean the venereal disease – an infection of the urinary tract and sex organs with chlamydia trachomatis. An infection with chlamydia trachomatis is one of the most common sexually transmitted diseases worldwide.

Symptoms of a chlamydia infection

The most typical symptoms of an infection with chlamydia are discharge, burning when urinating and genital itching. However, the symptoms are often very slight or go completely unnoticed. When noticeable, then usually 2-6 weeks after the infection. The symptoms differ between men and women.

Symptoms in women

In women, a chlamydia infection usually leads to inflammation of the urethra (urethritis) or the cervix (cervicitis). Indications of an infection are:

  • Slimy, often strong-smelling discharge
  • Frequent urge to urinate
  • Burning and pain during urination

Other possible symptoms of a chlamydia infection in women are:

Lower abdominal pain, genital itching, pain during sexual intercourse, anal discharge

Symptoms in men

The first sign of a chlamydia infection in men is an inflamed urethra (urethritis). This is shown by:

  • Burning and pain during urination
  • Slimy urethral discharge (from the opening of the penis), particularly in the morning
  • Genital itching

Other possible symptoms of a chlamydia infection in men are:

Pain during sexual intercourse, pain in the testicles, anal discharge

Symptoms of infection through anal and oral sex

In men and women, chlamydia can also enter the rectum through anal sex, which can lead to rectal inflammation (proctitis). Many patients don’t notice this as they don’t experience any symptoms. Others record symptoms such as anal discharge, anal itching or blood in the stool.

Oral sex can lead to pharyngitis caused by chlamydia. This is indicated by pain when swallowing and a sore throat. In some cases, chlamydia also affect the mucous membranes of the eyes and cause conjunctivitis.

Regardless of sexual preference, many chlamydia infections run their course with only minor symptoms or none at all.

Chlamydia infection without symptoms (asymptomatic)

According to the Federal Office of Public Health (FOPH), about 70% of women and 30% of men develop a chlamydia infection with only minor symptoms or none at all. The medical term for this is an asymptomatic infection. Since many of those affected experience hardly any or no symptoms, there’s a risk that the infection remains undetected and thus untreated for years. This can lead to serious consequences.

Complications and long-term consequences

In women, an undetected infection can cause bacteria to spread to the fallopian tubes and ovaries. The result is an inflammation of the fallopian tubes and ovaries (adnexitis) or pelvic inflammatory disease. In severe cases, patients face the risk of serious long-term consequences, including chronic lower abdominal pain and infertility. Experts estimate that every second case of involuntary childlessness is due to a chlamydia infection. In addition, if a woman does become pregnant, the risk of the fertilised egg implanting outside the uterus (ectopic pregnancy) increases.

In men, the bacteria can move up to the prostate and into the testicles and epididymis, resulting in an inflammation of the prostate (prostatitis), testicles and epididymis (orchitis and epididymitis). Infertility is a possible consequence.

Diagnosis: how to get tested for chlamydia

If you suspect you have chlamydia, you can go to your gynaecologist or urologist who will then perform a smear test. For women, this is a smear test of the cervix, and for men, a smear test of the urethra. The smear is then sent to the laboratory where analysts can determine the presence of an infection with chlamydia trachomatis.

Self-testing at home

Chlamydia tests that have been developed for people to use at home are now available in pharmacies or on the internet. However, because the results of such tests are not reliable, it’s preferable to get tested by a doctor.

Treatment of a chlamydia infection

A chlamydia infection is treated with antibiotics. The therapy lasts one to 14 days, depending on the antibiotic. To avoid the ping-pong effect of a renewed infection after the treatment is completed, the patient’s partner should also be included in the treatment.

How long are chlamydia contagious after treatment with antibiotics?

There are no universally valid guidelines for this because the treatment takes different lengths of time depending on the medication. Taking another test will put you on the safe side.

Reasons for infection

The main cause of a chlamydia infection is unprotected sexual intercourse, but there are others too.

  • Through unprotected sex
    The most common way of transmitting chlamydia is through unprotected sex (vaginal or anal sex). This is because of the direct contact with the infectious mucous membranes or body fluids. More rarely, throat infection occurs through oral sex.
  • Via petting and sex toys
    Indirect transmission via a smear infection during petting or when sharing sex toys is also possible.
  • Via the eyes and hands
    More rarely, chlamydia can be transmitted via infectious eye fluid (via the hands). However, this doesn’t lead to an infection of the urinary tract and sexual organs, but to conjunctivitis.
  • At birth
    If a pregnant woman has a chlamydia infection, the bacteria can be passed on to the newborn during birth.

Can you get chlamydia from kissing?

Normally not, because chlamydia aren't found in saliva. However, there’s a slight possibility of throat-to-throat transmission when tongue-kissing. A chlamydia infection in the throat usually heals on its own without any symptoms.

Can you catch chlamydia in the bathtub or swimming pool?

Infection of the sex organs via the water in a swimming pool is highly unlikely unless direct mucosal contact occurs through penetration. What you can pick up in a swimming pool, however, is bacterial conjunctivitis caused by chlamydia, also called swimming pool conjunctivitis.

When to see a doctor?

Seek the advice of a doctor in the following cases:

  • Itching, burning or discharge in the genital region
  • After having high-risk sex, i.e. in particular after unprotected sex outside a committed partnership (casual sex)
  • If your sexual partner is known or diagnosed to have a sexually transmitted infection or disease

What can I do myself?

  • Sexual contact only with condom, femidom or dental dams
  • Don’t put semen or blood in your mouth and swallow it
  • If you have changing or multiple sexual partners, talk to a doctor or other professional about sexually transmitted diseases and get advice on whether tests are necessary.


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