Sexually transmitted or venereal diseases are those diseases transmitted from person to person through sexual contact, which includes vaginal, anal and oral sex. However, this does not mean that this is the only route of distribution. Many of them can also be transmitted through blood, from the mother to the fetus or during breastfeeding. Although it is not quite correct from a terminological point of view and it is more correct to talk about sexually transmitted infections rather than diseases, the concept has taken hold and is in widespread use. They can be divided into five large groups, depending on the causative agent – bacterial, viral, fungal, protozoan and parasitosis. Bacterial infections include chlamydia, soft chancre, gonorrhea, granuloma inguinale; to viruses – the scourge of the XXI century – HIV, the human papilloma virus, which causes cervical cancer; the herpes simplex virus; hepatitis B and C, although the latter is rarely sexually transmitted. Protozoa, like bacteria, are single-celled organisms, but unlike them, they have a cell nucleus and a number of other cellular features that distinguish them from bacteria. The most significant sexually transmitted protozoan is Trichomonas vaginalis – the causative agent of trichomoniasis. Fungal infections are almost exclusively caused by Candida fungi. High sanitary and hygienic standards in Western countries have made venereal parasitosis very rare. This includes pubic lice and scabies, which can also be transmitted from person to person through sex. The enormous social importance of these diseases (or, more precisely, infections), especially HIV and hepatitis B, makes the fight against them a matter of state and even supranational policy. The economic burden they place on healthcare on a global scale is enormous. The death toll from these diseases probably exceeds the death toll from all armed conflicts in history. The human factor is no less significant – these are diseases that change millions of human destinies every year. Medicine is at a stage where HIV and hepatitis B – in 40-50% of cases – are incurable conditions. This means that the body’s immune mechanisms, combined with the best current treatment, cannot completely eradicate the infection. This makes prevention the granite foundation of any strategy to combat these diseases. Safe sex and sexuality education are at the forefront of this fight. While using a condom is a highly effective method of preventing such diseases, it is far from the only thing to do. Visiting reproductive health clinics or specialists, even in a stable relationship with a reliable partner, should be done at least once before switching to unprotected sex with a partner. This should also include full investigations for the diseases in question. They should be repeated after every unsafe contact with a new partner, although of course avoiding them is highly recommended. Also, if such an infection is detected,one must act conscientiously and responsibly towards the health of all former and/or current partners and notify them of one’s condition if there is a real risk that they may be infected. It is not moral to have unprotected sex if we know we have STDs. In some countries this is punishable as a felony. NEWS_MORE_BOX It should be known that there is a certain period of time between being infected with a given pathogen and testing positive in research. Within this window, tests looking for the causative agent give a false-negative result. During this time, deluding himself that he is not infected, a person can unknowingly transmit the infection to his sexual partners. For HIV, this window is 3 – 6 months, so after having risky sex with a new partner, you should wait at least three months before resuming unprotected sex with your regular partner. It is advisable to repeat the tests after another three months, although the accuracy of the first test is about 99%. False negative results after the first three months can be obtained in some more specific circumstances – presence of simultaneous hepatitis infection, etc. For hepatitis A, B and the human papilloma virus, vaccines have been created that should be administered in the absence of contraindications. It is desirable to do this before starting sexual life. It is extremely important that all this is included and well explained in schools, so that the youth are well acquainted with the nature, risks and, above all, the prevention of these diseases. The construction of a solid health culture must start from the school age, which is the only real chance in the near future to control the pandemic of HIV, hepatitis B and other sexually transmitted infections.which should be applied in the absence of contraindications. It is desirable to do this before starting sexual life. It is extremely important that all this is included and well explained in schools, so that the youth are well acquainted with the nature, risks and, above all, the prevention of these diseases. The construction of a solid health culture must start from the school age, which is the only real chance in the near future to control the pandemic of HIV, hepatitis B and other sexually transmitted infections.which should be applied in the absence of contraindications. It is desirable to do this before starting sexual life. It is extremely important that all this is included and well explained in schools, so that the youth are well acquainted with the nature, risks and, above all, the prevention of these diseases. The construction of a solid health culture, which is the only real chance in the near future to control the pandemic of HIV, hepatitis B and other sexually transmitted infections, must start from the school age.