General information about sexually transmitted diseases 

Sexually transmitted diseases (STD) are diseases transmitted through sex. They often appear symptomless but can still be transmitted to another person. You can get infected through unprotected sexual intercourse and oral and anal sex. Condoms provide effective protection against STDs.

The most common STDs in Finland are chlamydia, condyloma and herpes. Other STDs include gonorrhoea, syphilis, HIV, hepatitis B and C, chancres, and Mycoplasma genitalium infections.


In 2016, 14,321 new chlamydia cases were reported to the Finnish National Infectious Diseases Register. Chlamydia is the most frequently reported STD in Finland. In the same year, 416 gonorrhoea and 231 syphilis infections were reported in Finland. There were 183 new HIV infections, the majority of which were transmitted through sex. Following chlamydia, the diseases detected most frequently at STD clinics are condyloma and herpes, but no extensive data has been collected of their prevalence.


STDs can be completely symptomless. The symptoms of chlamydia and gonorrhoea include burning on urination, urinary frequency, urethral discharge, increased leucorrhoea, bloody postcoital discharge, and lower abdominal pain. Rectal, pharyngeal, and ocular symptoms may occur depending on the mode of transmission. However, rectal and pharyngeal infections are often symptomless.

Syphilis tends to cause a round, hard-edged ulcer in the transmission site in around one month. The ulcer is usually painless. Herpes infections are associated with superficial blisters. Condyloma causes wartlike changes. Hepatitis infections can cause yellow discoloration, which is usually first detected in the eyes. The initial symptoms of HIV infection are common for many diseases. These include fatigue and recurring bouts of fever.

If you experience symptoms associated with STDs, contact a healthcare unit.

Detection of STDs

Sexually transmitted diseases are diagnosed by a physician, usually at an STD clinic. Condyloma caused by the papillomavirus (HPV), and genital herpes caused by the Herpes simplex virus are usually diagnosed based on clinical findings, whereas the diagnosis of other sexually transmitted diseases requires laboratory testing. There is a separate test for each disease, and the incubation periods of the diseases must be taken into account in the testing.

Chlamydia and gonorrhoea infections can be diagnosed within approximately one week of the moment you were infected, but diseases like syphilis and HIV cannot be detected earlier than around one month after exposure. It is often necessary to collect additional samples, if the first sample does not indicate an infection.

Symptom-free persons can be screened for chlamydia and gonorrhoea from urine. For this purpose, there is a remote testing option available, allowing the patient to collect the sample themselves and send it to a laboratory for examination.

Interpretation of test results

A negative test result means that the sample does not contain signs of infection caused by the tested pathogen. If your test result is negative but you still suspect that you have a sexually transmitted disease, it is recommended to consider STDs other than the tested one. The need for further examination is determined by a physician at a healthcare unit. Make sure that enough time has passed between the moment you were infected and the sample collection.

A positive test result means that, depending on the test, either signs of a pathogen (e.g. chlamydia and gonorrhoea tests from urine) or antibodies to a pathogen (e.g. syphilis and HIV antibody tests from blood) can be detected in the sample. In such cases, a physician will determine the mode of treatment and any measures to prevent further infections.

If your home-collected chlamydia or gonorrhoea sample is positive, contact a health care unit.


Condoms provide effective protection against most STDs, if they are used throughout the sexual intercourse. It is also recommended to use a condom or dental dam during oral sex.