Sexually transmitted diseases (STDs) are diseases that are mainly passed from one person to another during sex. These diseases may be spread through vaginal, anal and oral sex.

There are different sexually transmitted diseases with a range of different symptoms and are more common in people aged between 15 and 30 years old.

Chlamydia or Gonorrhea are two of the most commonly reported bacterial sexually transmitted diseases. If left untreated, long-term infection can lead to fertility problems.
Syphilis can seriously affect organs such as the heart or the central nervous system.

Herpes is caused by two strains of the herpes simplex virus, type 1 and type 2. Blisters or bumps may appear on the genital area. Once the first outbreak of blisters has gone, the herpes virus hides away in nerve fibres near the infection site, where it remains dormant, causing no symptoms. Symptoms may come back later, but usually in less severe and shorter episodes.

Hepatitis refers to viral infections that cause inflammation of the liver. Hepatitis B and C can become chronic, life-long infections and can also be passed from an infected woman to her unborn child.

Human immunodeficiency virus infection (HIV) is transmitted primarily via sexual intercourse and also from mother to child during pregnancy, delivery, or breastfeeding. There is no cure or vaccine. However, antiretroviral treatment can slow the course of the disease and may lead to a near-normal life expectancy, although people with HIV are much more likely to get infections and tumors that do not usually affect people with working immune systems.

Genital Human Papillomavirus (also called HPV) is the most common sexually transmitted infection.
Some types of HPV can cause warts, while others can lead to cancers (HPV infection is a cause of nearly all cases of cervical cancer). Most people do not develop symptoms or health problems from it and the body's immune system clears HPV naturally. Vaccines can protect against HPV, it may also be detected using a Pap smear test.

Consistent and correct use of male latex condoms can reduce (though not eliminate) the risk of STD transmission. Other contraceptive methods could help prevent pregnancy, but may not provide protection against STDs, including HIV.