STIs can be transmitted through any kind of unprotected sex (oral, vaginal or anal), or through unprotected close sexual contact (mutual masturbation or sharing sex toys). STIs cannot be transmitted through kissing, shaking hands, sharing drinks, or by sitting on a toilet seat.

Many common STIs such as chlamydia or gonorrhoea often do not present any symptoms, meaning that many people do not know they are infected. However, even though there are no external symptoms, the STI can still cause irreversible damage to your body (such as making you unable to have children). Therefore, it’s really important to have regular sexual health screens and to use protection every time you have sex.

If you’re experiencing any symptoms or just want a check-up click here (Kent/Medway), or here (SW London) to find your local service. If you live in Wandsworth, Merton, or Richmond you can order a chlamydia & gonorrhoea home testing kit right here.

Many STIs have similar symptoms to other illnesses (such as thrush or a urinary tract infection), so it’s always important to visit your GP or a sexual health clinic if anything unusual is happening in your genital or anal regions.

If you are experiencing any of the following symptoms, you should visit your GP or sexual health clinic as soon as possible:

  • Stinging or burning sensation when you urinate
  • Unusual discharge from the penis, vagina or anus
  • Smelly discharge from the penis, vagina, or anus
  • A rash on or around the penis, vagina, or anus
  • Sore, tender or inflamed genitals
  • Testicle ache or pain
  • Abdominal ache or pain
  • Bleeding between periods or after sex
  • Itching, blisters or sores in the genital region or the mouth.
  • Pain during or after sex

Bacterial vaginosis (BV) is a common cause of unusual vaginal discharge. BV is not a sexually transmitted infection (STI), but it can increase your risk of getting an STI such as chlamydia.

Chlamydia is a bacterial STI and is very, very common amongst young people.

If untreated, it may cause infertility, ectopic pregnancy (when a fertilised egg implants and starts growing outside of the uterus) or pelvic inflammatory disease.

Symptoms, when they do appear, include a cloudy white discharge from the penis or vagina, and a burning or tingling sensation when you pee. However, many people who have Chlamydia do not know they are infected, so it’s really important to test regularly. The only way to know if you have Chlamydia is to do a Chlamydia test.

Chlamydia can be cured using tablet antibiotics.

Gonorrhoea another common bacterial STI that is caused by bacteria and can affect the urethra (the tube urine is passes through), rectum (back-passage), throat and, in women, the cervix and fallopian tubes.

Gonorrhoea may cause pelvic inflammatory disease in women and infection of the prostate gland in men.

Symptoms are similar to chlamydia but only appear in about 40% of cases, meaning that like Chlamydia, many people do not know when they have Gonorrhoea.

Gonorrhoea can be cured using tablet antibiotics and an antibiotic injection.

HIV is a viral sexually transmitted infection which attacks and weakens one’s immune system, making them susceptible to illness, infections, cancers, and other serious health issues.

While there is still no cure for HIV, there are many treatments available today, and people living with HIV in the UK can usually live normal lives and have safe sexual relationships.

People who are diagnosed with HIV soon after they become infected have the best chance of living long, healthy lives, so it’s really important that you test regularly for HIV if you have unprotected sexual contact.

Genital herpes is a common sexually transmitted infection (STI). It is caused by a virus called Herpes simplex, closely related to the one that causes cold sores around the mouth.

Like genital warts, treatments are available for the sores which are caused by herpes, though there is no treatment for the virus itself. A person who becomes infected with herpes may only ever have one outbreak of sores, or they may have multiple outbreaks throughout their lives.

The herpes virus can be passed on even if before any sores are visible, so it’s very important to always use a condom as it drastically reduces the likelihood of transmission.

Genital warts are the most common viral sexually transmitted infection (STI) in the UK. They are caused by the human papilloma virus (HPV) which can be passed on during sexual contact and can affect both the genital and rectal areas, as well as the mouth and throat.

There is currently no cure for HPV, although treatment is available to get rid of the warts.

If you contract the strains of HPV which lead to genital warts, you may get only one outbreak of warts or you may get multiple outbreaks throughout your lifetime.

Hepatitis means 'inflammation of the liver'. There are three main viral strains (A, B, C)

Hep A is passed through ingestion of faecal matter, and, while the least serious, can still make you very ill.

Hep B is passed through blood, semen, vaginal fluid and saliva and can cause serious harm to the liver. Treatments are available, though success rates vary.

Hep C is the most dangerous (in certain cases even fatal) and is usually passed through sharing needles or, sometimes, through unprotected sexual intercourse.

Pubic lice (also known as crabs due to their appearance) are tiny parasites that live on coarse human body hair (such as pubic hair) and spread through close body contact.

Symptoms include itching and inflammation in the affected areas, black powder in your underwear and/or tiny blood spots on your clothing or skin.

Scabies is caused by tiny parasitic mites that burrow into the skin and lay eggs.

It is usually transmitted through direct skin contact or, less frequently, through sharing bedding or towels.

Syphilis is a serious bacterial STI which can be transmitted through sexual activity and direct skin contact.

Symptoms may (but do not always) include sores around the genital or anal area, a painless rash and general flu-like symptoms.

It is important that you get tested as the infection can, if left untreated, cause irreversible damage to your body.

There are a number of genital infections that are not transmitted through sexual contact, yet have similar symptoms. It is important to undergo a full sexual health check to ensure that you get the correct treatment. Unlike thrush and BV, STIs will not go away by themselves.

Trichomonas vaginalis (shortened to TV) is a tiny parasite which causes an infection in the vaginal canal or the urethra (in both men and women).

It is easily passed through sexual contact and symptoms (if there are any) can often be confused with chlamydia. Testing is therefore strongly recommended.

Urethritis is when the tube that carries pee from the bladder out of the body (urethra) becomes swollen and sore. It's often caused by a sexually transmitted infection (STI). It's important to get it treated to avoid it spreading to other people.

Gonococcal urethritis is when the infection is caused by gonorrhoea.

Non-gonococcal urethritis (NGU) or non-specific urethritis is more common. This is when the infection is caused by something other than gonorrhoea, such as chlamydia.