STI Conditions

Chlamydia is the most common bacterial sexually transmitted infection in the UK. It is easily treated with antibiotics but can cause serious complications if left untreated.

Gonorrhoea is a bacterial STI that can infect the genitals, rectum, and throat. It's becoming increasingly resistant to antibiotics, making early detection crucial.

HIV is a virus that attacks the immune system. With modern treatment (antiretroviral therapy), people with HIV can live long, healthy lives and cannot pass on the virus when treatment is effective.

Syphilis is a bacterial STI that progresses through stages if untreated. It's easily treated with antibiotics in early stages but can cause serious health problems if left untreated.

Herpes is a common viral infection caused by the herpes simplex virus (HSV). There are two types: HSV-1 (usually oral) and HSV-2 (usually genital). While there's no cure, outbreaks can be managed with antiviral medication.

Hepatitis A is a viral liver infection spread through contaminated food, water, or close contact including sexual activity. It usually resolves on its own within a few months and does not cause chronic infection. A highly effective vaccine is available.

Hepatitis B is a viral infection that attacks the liver. It can be acute or become chronic, potentially leading to cirrhosis or liver cancer. A highly effective vaccine is available and is routine in the UK childhood immunisation programme.

Hepatitis C is a blood-borne viral infection that affects the liver. It often becomes chronic but can now be cured in over 95% of cases with modern antiviral treatment. Many people are unaware they are infected for years.

HPV is the most common sexually transmitted infection worldwide. There are over 100 strains — some cause genital warts, while certain high-risk strains can lead to cervical, anal, and throat cancers. Most infections clear naturally within 2 years.

Genital warts are caused by low-risk strains of HPV (mainly types 6 and 11). They appear as small fleshy growths around the genitals or anus. While not dangerous, they can be distressing and are highly contagious.

Mycoplasma genitalium is a small bacterium that can infect the urogenital tract. It is recognised as an increasingly common cause of urethritis, cervicitis, and pelvic inflammatory disease. Antibiotic resistance is a growing concern.

Ureaplasma is a type of bacteria that commonly lives in the urogenital tract. While often harmless, it can sometimes cause urethritis, vaginal infections, and complications in pregnancy. Overgrowth or presence in symptomatic patients may require treatment.

Trichomoniasis is caused by a tiny parasite called Trichomonas vaginalis. It is one of the most common curable STIs worldwide, primarily affecting the vagina in women and the urethra in men.

Non-gonococcal urethritis (NGU) is inflammation of the urethra not caused by gonorrhoea. It can be caused by chlamydia, mycoplasma, ureaplasma, or other organisms. It is one of the most common conditions seen in sexual health clinics in men.

Bacterial vaginosis (BV) is the most common vaginal condition in women of reproductive age. It occurs when the normal balance of vaginal bacteria is disrupted, leading to overgrowth of certain bacteria. It is not strictly an STI but is associated with sexual activity.

Vaginal thrush is a common yeast infection caused by Candida species (usually Candida albicans). It is not an STI but can cause uncomfortable symptoms. Most women experience thrush at least once in their lifetime.

Pelvic inflammatory disease (PID) is an infection of the female reproductive organs (womb, fallopian tubes, and ovaries). It is usually caused by bacteria from STIs such as chlamydia or gonorrhoea spreading from the vagina or cervix.

Epididymitis is inflammation of the epididymis (the coiled tube behind the testicle). In sexually active men under 35, it is most commonly caused by STIs such as chlamydia or gonorrhoea. It causes testicular pain and swelling and requires prompt treatment.

Molluscum contagiosum is a viral skin infection caused by a poxvirus. It produces small, firm, dome-shaped bumps with a dimple in the centre. In adults, it is commonly spread through sexual contact and appears in the genital area.

Pubic lice (crabs) are tiny parasitic insects that live in coarse body hair, particularly pubic hair. They are spread through close body contact, usually during sex. While uncomfortable, they are easily treated and do not carry disease.