Sexual health includes preventing, recognizing and treating sexually transmitted infections (STIs), as well as having access to reliable testing, vaccination and medical care. Many STIs cause few or no symptoms, so testing can be important after possible exposure.
Common sexually transmitted infections
- Chlamydia — a common bacterial STI that may cause no symptoms but can lead to complications if untreated.
- Gonorrhea — a bacterial infection that can affect the genitals, rectum or throat.
- Syphilis — a bacterial infection that develops in stages and can cause serious complications without treatment.
- Genital Herpes — a viral infection that can cause recurrent painful blisters or sores.
- Human Papillomavirus (HPV) — a very common group of viruses; some types cause genital warts and others can contribute to cancer.
- Genital Warts — growths caused by certain types of HPV.
- HIV — a virus that affects the immune system and can be controlled effectively with modern treatment.
- Hepatitis B — a viral infection affecting the liver that can also be transmitted sexually.
- Mycoplasma Genitalium — a bacterial STI that can cause urethritis, cervicitis and pelvic inflammatory disease.
- Pubic Lice — small parasitic insects that live in coarse body hair and are commonly spread through close sexual contact.
Possible symptoms
Symptoms can include unusual vaginal or penile discharge, pain or burning when urinating, genital sores or blisters, pelvic pain, pain during sex, bleeding between periods, testicular pain or swelling, genital itching or a new rash. However, an STI may be present without symptoms.
Testing and treatment
Testing may involve urine, blood or swab samples depending on the infection and type of sexual exposure. Bacterial STIs are generally treated with appropriate antibiotics. Viral infections may be managed with antiviral medicines, monitoring or other treatment. Sexual partners may also need testing or treatment.
Prevention
Condoms and other barrier methods reduce the risk of many STIs when used correctly. Vaccination can prevent hepatitis B and many HPV-related diseases. Regular testing is important for people with new or multiple partners or other risk factors, and testing should be considered after a possible exposure.
When to seek urgent care
Seek urgent medical care for severe pelvic or lower abdominal pain, severe testicular pain or swelling, high fever with genital or pelvic symptoms, or serious illness. After a recent possible exposure to HIV, seek medical advice promptly because post-exposure prophylaxis (PEP) must be started as soon as possible.
Sources and further reading
Last reviewed: 4 September 2026. This page provides general health information and does not replace individual medical assessment, testing or treatment.