Sexually transmitted infections (STIs) are passed on during unprotected sexual contact. While the symptoms are often unpleasant, if caught early most can be treated quickly and easily.

However, without treatment, they can get worse and have serious consequences. By ignoring STIs and not getting yourself checked out each time you have unprotected sex, you put yourself and others at risk.

What follows is a guide to some of the most common STIs in the UK, including their symptoms, treatments and potential risks if left untreated.

Please note that whilst pubic lice or genital herpes may be diagnosed and treated using our video platform, other STIs will require further tests to confirm the infection. If you already have a positive test result, our GPs can treat Chlamydia infections but Gonorrhoea, HIV and Syphilis are best treated at your local Sexual Health clinic. 

Chlamydia is the most common STI in the UK. It mainly affects young people, with 70 per cent of cases found in under-25s.

It can be difficult to detect, as the majority of those infected won’t experience any symptoms. However, men and women may experience a burning sensation when they urinate, or find an unpleasant discharge coming from their penis or vagina.

Some women suffer from stomach pain or bleeding before or during sex, while their periods might be heavier than normal. Men can find that their testicles become swollen and/or painful.

It’s important to get tested after you’ve had unprotected sex, even if you don’t experience symptoms. Allowing the infection to stay in your system can have catastrophic consequences, particularly for women who can suffer from infertility, ectopic pregnancy and reactive arthritis. Pregnant women also risk harm to the foetus, such as conjunctivitis or pneumonia.

Chlamydia is treated with antibiotic tablets, along with a follow-up appointment to check that treatment has been successful.

The second most common STI in the UK, genital warts are passed on through skin-on-skin contact, meaning you can catch them even if you use a condom.

You will find small, hard lumps around your genitals that can be itchy or bleeding. They can take up to three months to appear, during which time you will still be infected with the virus and can still pass genital warts on to someone else. However, having the virus does not necessarily mean you will get genital warts.

While the warts will not harm your health, they are pretty unsightly and you’ll naturally want them out of the way. Treatments range from creams to more serious procedures such as cryotherapy and laser surgery.

Gonorrhoea shares many similarities with chlamydia. The symptoms are largely the same for both genders, while half of women and one in 10 men won’t experience any.

The treatment for gonorrhoea consists of a course of antibiotics. In this case, you may find it’s given as one tablet and one injection.

Once again, leaving gonorrhoea untreated has many of the same risks as chlamydia, with potentially serious pregnancy and fertility consequences.

There’s a common misconception that lice are caused by poor hygiene. In the case of pubic lice (also known as ‘crabs’), this is not the case, they are simply the result of sexual contact and can affect anyone.

The lice set up home in your pubic hair and lay their eggs, which take up to a week to hatch. Adult lice are around two millimetres long and you might be able to see them in your hair.

Other symptoms include itching and blue or red bite marks, while irritated skin can occur if you scratch a lot.

Your treatment will likely be some sort of shampoo that will need to be applied twice over the course of a week, to kill off any live lice and any eggs that hatch later.

Caused by the same virus that gives you cold sores, genital herpes can lead to blisters on your genitals and the surrounding area, which can sometimes lead to pain when urinating. However, eight out of 10 people who contract herpes will never experience any sores.

The herpes virus can’t be cured and stays in your system forever. People who experience symptoms will likely find they recur multiple times over the next few years. Triggers for an outbreak of genital herpes include stress, illness, alcohol and a generally weak immune system.

If you do get sores, there are antiviral tablets that can help manage them, which might have to be taken as much as five times a day if the problem is particularly bad.

Syphilis causes sores to develop on the genitals or around the mouth. Contact with these sores during sex is the most likely way for the virus to be passed on.

As well as sores, you might experience a rash on your hands and feet, white patches inside your mouth and general flu-like symptoms.

If caught early, syphilis can be treated with a simple course of antibiotics. However, if you ignore the symptoms, syphilis can do very serious, irreversible damage and lead to conditions such as meningitis, stroke, dementia, sight problems, heart problems and even death.

Human immunodeficiency virus (HIV) attacks your immune system and makes it more difficult to fight off illnesses that would otherwise not cause you problems.

If you get HIV, you will likely feel like you have a very bad flu and may also get a rash. While this will die down, it’s important to know that HIV will remain in your system and needs treatment before it gets worse. If your immune system reaches a point where it can’t fight off any more infections, this is known as AIDS.

As far as treatment goes, there’s no cure for HIV, but symptoms can be effectively managed with antiviral medication that you will likely need to take for the rest of your life.

STIs can potentially cause lasting damage. If you’re worried you might have an STI, or you’d like to know more about the best ways to protect yourself against them, consult one of our doctors today for advice on the next steps you should take.