Types of STIs

We've got information on the most common sexually transmitted infections (STIs) in the UK, including chlamydia, gonorrhoea and HIV. Some infections and conditions can be passed on during sex or are caused by existing STI’s but are not technically classed as STI’s themselves. They can still seriously affect your health so it’s really important to be aware of these too. You'll find more information on all of these infection in this section. Here’s what you might be dealing with.

In this section
  • Chlamydia

    Chlamydia is one of the most common STIs in the UK. In 2013, more than 200,000 people tested positive for chlamydia in England and the majority were under 25. It is very easily cured but, if left untreated, it can cause serious reproductive and health problems.

  • Epididymo-orchitis

    Epididymo-orchitis is the inflammation of the epididymis tube, which is a tube located at the back of the testicles that stores and carries sperm. It only affects men and can be very painful, with serious health problems, if left untreated.

  • Genital herpes

    Genital herpes or herpes simplex virus (HSV) is a very common sexually transmitted infection (STI). There are two types of the virus, HSV type 1 and HSV type 2; both types can cause genital herpes.

  • Genital warts

    Genital warts is a sexually transmitted infection which is caused by the HPV virus. Genital warts are small fleshy growths or bumps on the genitals. They are usually painless, although they can be unpleasant to look at and distressing for some people with the infection.

  • Gonorrhoea

    Gonorrhoea is the second most common STI in the UK, after chlamydia. The majority of those who test positive are under 25. It is very easily cured but, if left untreated, gonorrhoea can cause serious reproductive and health problems. Gonorrhoea is usually treated with a single antibiotic injection followed by some tablets.

  • Hepatitis B

    Hepatitis is the inflammation of the liver. Hepatitis B is one of a group of viruses that can cause this. There are two stages of the infection – “acute” which lasts for one to three months and chronic infections which last for longer.

  • Hepatitis C

    Hepatitis is the inflammation of the liver. Hepatitis C is one of a group of viruses that can cause this and is the most common type of viral hepatitis in the UK. If left untreated, it can cause serious liver damage.

  • HIV

    Human immunodeficiency virus (HIV) is a virus that attacks the immune system and weakens the body’s ability to fight other infections. About 70-90% of people living with HIV have no symptoms and carry the infection without knowing.

  • Lymphogranuloma venereum (LGV)

    LGV is also known as ‘lymphogranuloma venereum’. It's a form of chlamydia that attacks the lymph nodes. It is very rarely seen in heterosexual (straight) men and women in the UK, but cases are being seen among gay and bisexual men in growing numbers. Most cases of LGV can be treated with antibiotics, as long as the infection is treated early enough. However, left untreated, LGV can cause lasting damage that may require surgery.

  • Pelvic inflammatory disease (PID)

    Pelvic inflammatory disease (PID) is an infection of the female reproductive organs. If can be treated quickly and effectively if caught early. Left untreated, it can lead to infertility. It's a common condition which mostly affects sexually active women, aged 15 to 24.

  • Syphilis

    Syphilis is a bacterial infection that spreads easily and can have long-term health implications. While less common than some STIs, numbers are rising. It is usually caught by having sex with someone who is infected (including oral sex) and occurs in three distinct stages.

  • Trichomonas vaginalis

    Trichomonas vaginalis (TV) is tiny parasite, which can live in the vagina as well as in the urethra (tube that carries urine from your bladder out of the body) of both women and men. The infection is easily passed from one person to another through sexual contact. Diagnosis can be made fairly easily in females but is often difficult in males. TV is unlikely to go away without treatment but can be effectively treated with antibiotics.

  • Urethritis (NGU)

    Urethritis is inflammation (swelling) of the urethra – the tube that carries urine from the bladder out of the body. It is commonly caused by chlamydia. It is called non-gonococcal urethritis (NGU) when not caused by Gonorrhoea. A clinical diagnosis of NGU is possible in males but not in females.

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