Sexually transmitted infections

Most sexually active people experience a sexually transmitted infection (STI) at some point in their lives. According to the WHO, there are 1 million transmissions per day worldwide. Widespread STIs include chlamydia infections, herpes, fungal infections and genital warts, but gonorrhea and syphilis are also becoming more common again. The possible consequences range from annoying itching to life-threatening conditions. Regular testing and treatment in the event of a diagnosis are important.

Key facts about sexually transmitted infections

  • Sexually transmitted infections are transmitted during sex. They include chlamydia infections, gonorrhoea and syphilis, for example.
  • They are transmitted mainly during vaginal, anal and oral sex, but also during other practices, such as when sharing sex toys.
  • Condoms and femidoms reduce the risk of an infection, but do not provide full protection.
  • Sexually transmitted infections are often asymptomatic. If symptoms do occur, they include discharge, itching or skin rash on the genitals and the anus.
  • Sexually transmitted infections are usually well treatable, but can have severe health consequences if left untreated.
  • Sexually active people who frequently change partners should therefore get tested for sexually transmitted infections at least once a year. You can protect yourself from some infections by using condoms or getting vaccinated. All the infections mentioned can be treated effectively. If you have sex with different partners, you should therefore get tested for undiagnosed infections at least once a year.


Sexually transmitted infections (STIs) are also referred to as sexually transmitted diseases (STDs).

Common sexually transmitted infections and their causes

Sexually transmitted infections are widespread and many sexually active people are affected by them at least once in life. STIs are caused by various pathogens, such as viruses, bacteria or fungi.

The most common sexually transmitted infections include:

  • Chlamydia infections
  • Syphilis
  • Gonorrhoea, colloquially known as the clap (caused by bacteria)
  • HPV and genital warts
  • Genital herpes
  • Hepatitis B (caused by viruses)
  • Fungal infections
  • Trichomonas infections


Sexually transmitted infections often cause no symptoms and therefore remain undiagnosed. The most common symptoms include itching in the genital area, urethral or vaginal discharge, skin rash / ulceration in the genital area and swelling or pain in the lower abdomen.

If symptoms are present, it is important to get tested to detect STIs.

Testing and diagnosis

To detect STIs early, even if they do not cause any symptoms, it is important to get tested on a regular basis – at least once a year. People who frequently change sex partners are recommended to get tested every six months.

There are various methods for detecting sexually transmitted infections, including visual diagnosis, smear test, stool test, urine test and blood test.


Sexually transmitted infections are usually well treatable. If not diagnosed and treated, however, they can lead to severe conditions in the long term.

The treatment options include antibiotics, antiviral medication, creams, ointments and surgical procedures (such as surgical removal of genital warts).


You can effectively protect yourself from some infections by using condoms/femidoms or getting vaccinated. All the infections mentioned can be treated effectively and can often be cured completely once they are detected.

A vaccination provides the best protection against hepatitis A and B and the most important pathogenic HPV strains. Some sexually transmitted infections can be transmitted despite taking precautionary measures, such as using condoms or femidoms. Since symptoms are often not present or not noticed, people who have sex with different partners should get tested once a year, even if they do not have any symptoms, and treated, if necessary.