STIs (sexually transmitted infections)

STIs are infections that can be passed from one person to another through unprotected sex (sex without a condom). Some STIs can also be passed to partners through oral sex.

It is quick and simple to test for an STI, many STIs can be treated with antibiotics. It is a good idea to have an STI test after unprotected sex or when you change partners. 

Resistant gonorrhoea diagnosed in the UK – the facts 

Chlamydia is one of the most common sexually transmitted infections (STIs) in the UK. It is a bacterial infection caused by the bacterium Chlamydia trachomatis and is particularly common in sexually active teenagers and young adults. Most people with chlamydia don’t notice any symptoms and don’t know they have it but can still pass it on to others through unprotected sex.

If you do develop symptoms, you may experience some or all of the following:

  • Pain when urinating,
  • Unusual discharge from the vagina, penis or rectum (back passage)
  • Pain in the tummy, bleeding during or after sex, and bleeding between periods (women)
  • Pain and swelling in the testicles (men)

Treatment for chlamydia is usually with antibiotic tablets, read more about chlamydia at NHS Choices.

Order an STI test kit

Genital herpes is a common infection caused by the herpes simplex virus (HSV). It causes painful blisters on the genitals and the surrounding areas. HSV can affect any mucous membrane (moist lining), such as those found in the mouth (cold sores).

It is passed by close contact and so is referred to as a sexually transmitted infection.
Genital herpes is a chronic (long-term) condition.

The virus remains in your body and can become active again. The average rate of recurrence is four to five times in the first two years after being infected. However, over time, it tends to become active less frequently and each outbreak becomes less severe.

There are often few or no initial symptoms, at least eight out of 10 people who carry the virus are unaware they have been infected because. However, certain triggers can activate the virus, causing an outbreak of genital herpes.

Treatment: There is no cure for HSV but medication is available to help prevent the HSV from multiplying.

Read more about genital herpes on NHS Choices

Genital warts are the result of a viral skin infection caused by the human papilloma virus (HPV). The HPV is not a single virus, but a family of more than 100 different strains of viruses. Different strains usually affect different parts of the body, including the hands or feet.

Although around 30 different types of HPV can affect the genital skin, most cases are caused by just two types (type 6 and type 11). The types of HPV that cause visible genital warts do not cause genital cancer, some other strains of HPV can cause cervical cancer.

Symptoms – visible warts (small fleshy growths, bumps or skin changes) that appear on or around the genital or anal area. They are usually painless and do not pose a serious threat to health, but they can be unpleasant to look at and cause psychological distress.

Treatment for genital warts depends on how many warts you have and where they are. Several treatments are available, such as liquids or creams and freezing the warts (cryotherapy).

Read more about genital warts at NHS Choices

Gonorrhoea is caused by the bacteria Neisseria gonorrhoeae. It used to be known as ‘the clap’ and is easily passed between people through unprotected vaginal, oral or anal sex. It can also be passed on by sharing vibrators or other sex toys that haven’t been washed or covered with a new condom each time they’re used.

Typical symptoms of gonorrhoea include;

  • A thick green or yellow discharge from the vagina or penis
  • Pain when urinating and
  • Bleeding between periods (in women)

Treatment is usually with an injection and antibiotic tablets. It is recommended that you attend a follow-up appointment two weeks after treatment to check you are clear of the infection.

Read more about Gonorrhoea at NHS Choices

Hepatitis is the term used to describe inflammation of the liver. It’s usually the result of a viral infection or liver damage caused by drinking alcohol. There are several different types of hepatitis, most of which are outlined below. Some types will pass without any serious problems, while others can be long-lasting (chronic) and cause scarring of the liver (cirrhosis), loss of liver function and, in some cases, liver cancer.

Hepatitis A

Hepatitis A is caused by the hepatitis A virus. It’s usually caught by consuming food and drink contaminated with the poo of an infected person and is most common in countries where sanitation is poor. Hepatitis A usually passes within a few months, although it can occasionally be severe and even life-threatening. There’s no specific treatment for it, other than to relieve symptoms such as pain, nausea and itching.

Vaccination against hepatitis A is recommended if you are a man who has sex with other men. This can be provided as part of you sexual health check-up.

If you are planning on travelling to an area where the virus is common, such as the Indian subcontinent, Africa, Central and South America, the Far East and Eastern Europe then we would recommend contacting your GP and having this vaccination as part of you travel plans.

Read more about hepatitis A from NHS Choices

Hepatitis B

Hepatitis B is caused by the hepatitis B virus, which is spread in the blood of an infected person. It’s a common infection worldwide and is usually spread from infected pregnant women to their babies, or from child-to-child contact. In rare cases, it can be spread through unprotected sex and injecting drugs. Hepatitis B is uncommon in the UK and most cases affect people who became infected while growing up in part of the world where the infection is more common, such as Southeast Asia and sub-Saharan Africa.

Most adults infected with hepatitis B are able to fight off the virus and fully recover from the infection within a couple of months. However, most people infected as children develop a long-term infection. This is known as chronic hepatitis B and it can lead to cirrhosis and liver cancer. Antiviral medication can be used to treat it.

In the UK, vaccination against hepatitis B is recommended for people in high-risk groups, such as people who inject drugs, men who have sex with men, sex workers and people who pay for sex. This can be provided as part of you sexual health check-up.

If you are planning on travelling to part of the world where the infection is more common then we would recommend contacting your GP and having this vaccination as part of you travel plans.

Read more about hepatitis B from NHS Choices

Hepatitis C

Hepatitis C is caused by the hepatitis C virus and is the most common type of viral hepatitis in the UK. It’s usually spread through blood-to-blood contact with an infected person. In the UK, it’s most commonly spread through sharing needles used to inject drugs. Poor healthcare practices and unsafe medical injections are the main way it’s spread outside the UK. It is uncommon for hepatitis C to be passed through sex. Hepatitis C often causes no noticeable symptoms, or only flu-like symptoms, so many people are unaware they’re infected.

Around one in four people will fight off the infection and be free of the virus. In the remaining cases, it will stay in the body for many years. This is known as chronic hepatitis C and can cause cirrhosis and liver failure.

Chronic hepatitis C can be treated with very effective antiviral medications, but there’s currently no vaccine available.

Read more about hepatitis C from NHS Choices

If you have been in contact with someone who has recently been diagnosed with hepatitis A or hepatitis B then let the clinic staff know as you may be offered these vaccinations to protect you.

Human immunodeficiency virus (HIV) is a virus that attacks the immune system, and weakens your ability to fight infections and disease. It is most commonly caught by having unprotected sex (sex without a condom) but can also be passed on by sharing infected needles and other injecting equipment, and from an HIV positive mother to her child during pregnancy, birth and breastfeeding.

HIV is found in the body fluids of an infected person, which includes semen, vaginal and anal fluids, blood, and breast milk. It is a fragile virus and does not survive outside the body for long. If a person is on HIV treatment, the number of viruses in their system may be reduced to a level that is undetectable, making it very unlikely that they can pass on the infection.

Being diagnosed with HIV today is very different today than it was 20 or 30 years ago. HIV is no longer a death sentence and people living with HIV can live long and healthy lives.

Treatment: There is no cure for HIV, but there are treatments to enable most people with the virus to live a long and healthy life. Treatment for HIV (antiretroviral drugs), works by stopping the virus replicating in the body, allowing the immune system to repair itself and preventing further damage. These medicines come in the form of tablets, which need to be taken every day.

If you think you have been exposed to HIV, emergency anti-HIV medication called PEP (post-exposure prophylaxis) may be provided to reduce your chances of becoming infected, this works best if given within 72 hours of exposure.

If you think you have been exposed to HIV you must go to your nearest sexual health clinic or hospital emergency department (A&E) within 72 hours of exposure.

Read more about HIV on NHS Choices

Order a HIV test kit

Lymphogranuloma venereum, or LGV, is a curable sexually transmitted infection caused by a bacterium from the chlamydia family.

LGV can infect the genitals, anus, rectum, throat or lymph glands in the groin. In some cases LGV causes a fever, abdominal pain and a feeling of being generally unwell.

Men may notice a discharge of mucus and/or blood from the rectum, pain when they pass a motion or have passive (receptive) anal sex. They may be constipated or have loose motions or a feeling that they have not completely emptied their bowels after passing a motion. Some men notice an open sore or ulcer near the anus or on the penis.

LGV in women is very rare in the UK. Some people with LGV may not get any symptoms but they can still pass the infection on to their sexual partners. Prompt treatment is recommended to prevent more serious problems. If not treated, LGV can cause permanent swelling of the genitals and blockage of the bowel.

LGV used to be very rare in Europe. Most cases were seen in people who had had sex in tropical regions such as parts of Africa and Asia. However, in 2004 LGV outbreaks were reported in the Netherlands. These infections affected men who have sex with men (MSM), especially HIV-positive MSM. LGV quickly spread to other European countries including the UK. LGV remains very rare in heterosexual (straight) people in the UK.

LGV is usually treated with an antibiotic called doxycycline which is taken twice a day for three weeks. Sometimes different antibiotics are used.

A leaflet explaining more about LGV is available here

Molluscum contagiosum is a vial skin condition.

The molluscum contagiosum virus is transmitted through close skin contact, including genital contact during sex.

The most common symptom of molluscum contagiosum is the appearance of small spots or abnormal patches on the skin. This is usually the only symptom. In sexually active adults, the spots usually appear on the groin area, spreading upwards over the pubic and abdominal (tummy) areas, genitals and inner thighs.

The spots are usually firm, raised and painless. You may notice that some of the spots have a tiny grey head in the center and look pearly. This head may rupture (split), causing a thick yellowy-white substance to escape. This substance is highly infectious so you should avoid handling or squeezing the spots, or shaving the skin in that area, as this can spread the infection to other parts of the body.

The spots do not usually leave scars, but you may notice that each one leaves a tiny patch of lighter skin or a small pitted mark.

Molluscum contagiosum is diagnosed during a physical examination.

In most cases, molloscum contagiosum will go away within 18 months without the need for treatment. However, you are likely to pass on the infection to sexual partners so if you’re found to have the infection you will often be offered treatment with cryotherapy (freezing) with liquid nitrogen, which has a rapid effect.

Urethritis is an inflammation of the urethra – the tube that carries urine from the bladder out of the body. It is often caused by an infection but there are many environmental (non-infectious) causes. Urethritis is sometimes referred to as non-specific urethritis (NSU) when no cause can be found. In women, NSU rarely has any symptoms.

Symptoms in men include:

  • A painful or burning sensation when urinating
  • The tip of the penis feeling irritated and sore
  • A white or cloudy discharge from the tip of the penis

Treatment – You may be given a course of antibiotics, however sometimes NSU is caused by non-infectious causes that do not respond to antibiotics.

Read more about NSU at NHS Choices

Pubic lice (Phthirus pubis) are tiny parasitic insects that live on coarse human body hair, such as pubic hair. They spread through close body contact, most commonly sexual contact. It is also possible for pubic lice to be spread through sharing clothes, towels and bedding.

After you get pubic lice, it can take several weeks before symptoms appear. The symptoms include:

  • Itching in the affected areas
  • Inflammation or irritation in the affected areas caused by scratching
  • Black powder in your underwear
  • Blue-coloured spots on your skin where the lice are living, such as on your thighs or lower abdomen (these are caused by lice bites)
  • Tiny blood spots on your underwear or skin

Treatment: You can treat pubic lice yourself at home by using a special type of lotion, cream or shampoo. The treatment is applied to the affected area and sometimes the whole body. It usually needs to be repeated after three to seven days.

Your doctor or pharmacist can advise you about which treatment to use and how to use it. It’s important to follow this advice.

Read more about public lice on NHS Choices

Syphilis is caused by the bacterium Treponema pallidum and is usually caught by having unprotected sex with someone who is infected. The syphilis-causing bacteria can enter your body if you have close contact with an infected sore, normally during vaginal, anal or oral sex, or by sharing sex toys with someone who is infected. It may also be possible to catch syphilis if you are an injecting drug user and you share a needle with somebody who is infected.

Symptoms – are the same for men and women, and can be difficult to recognise. They are often mild, which means you can pass on the infection without knowing you have it. There are 3 stages of the disease (primary, secondary and tertiary). Syphilis can be passed on at any stage but is most infectious in the primary or secondary stages.

Treatment for syphilis is usually with antibiotic injections.

Pregnant women can pass the condition on to their unborn baby. If untreated, syphilis can cause serious health problems for the mother and her baby, or cause miscarriage or stillbirth. This is why all pregnant women are offered a blood test to check if they have syphilis as part of routine antenatal screening.

Read more about syphilis on NHS Choices

Thush is a very common condition caused by yeast which lives harmlessly in the female vagina. Occasionally the yeast overgrows and this overgrowth can cause signs and symptoms.

Though thrush can be passed on during sex, it is not a sexually transmitted infection as such, and it can affect people even when they do not have sex.

Thrush is more common during pregnancy and in people with diabetes, or HIV. It can also develop when taking certain antibiotics, or chemotherapy treatments that affect the immune system. Wearing tight clothing can also enable thrush to develop.

Thrush can be made worse by products that may cause irritation of the vagina, such as vaginal deodorant or bubble bath.

Women might notice:

  • itching, soreness and redness around the vulva, vagina and anus
  • vaginal discharge may become very thick, like cottage cheese
  • urinating and having sex can be painful

Men might notice:

  • irritation, burning or itching under the foreskin or around the tip of the penis
  • redness of the genital skin or a spotty rash on the head of the penis
  • a discharge under the foreskin, or swelling

Thrush is often diagnosed by how it looks, but it can also be tested for by taking swabs from the affected area.

Thrush can clear on its own, especially in people who don’t have any symptoms.

You can buy anti-fungal cream and pessaries (specially shaped pills which are inserted into the vagina) from a pharmacist, who will advise you on how to use these treatments. However, if the symptoms do not resolve with these simple measures, you should see your GP or come to a sexual health clinic for a check up.

Trichomonas Vaginalis (TV) is a curable sexually transmitted infection (STI) caused by a protozoon. Protozoa are tiny germs similar to bacteria.

TV can infect the vagina, urethra (water passage), and underneath the foreskin. Women may notice a change in vaginal discharge, and may have vulval itching or pain on passing urine. Men may notice a discharge from the tip of the penis, pain on passing urine or soreness of the foreskin. Over 90% of TV cases are diagnosed in women. If you have TV we recommend that you have tests for other STIs including chlamydia, gonorrhoea, syphilis and HIV.

You can get TV through unprotected vaginal sex, insertion of fingers into the vagina or sharing sex toys with someone who has TV

Women may not notice anything wrong but they can still pass on TV to their sexual partner. Some women may notice one or more of the following:

  • increased vaginal discharge
  • an unpleasant vaginal smell
  • ‘cystitis’ or burning pain when passing urine
  • vulval itching or soreness
  • pain in the vagina during sex

Most men will not feel anything wrong but they can still pass TV on to their sexual partner. Some men may notice one or more of the following:

  • a discharge from the tip of the penis
  • a burning pain when they pass urine
  • they want to pass urine more often than normal
  • soreness around the foreskin

TV can be easily treated with antibiotics.

A leaflet explaining more about TV is available here