Research has shown that sex has a positive effect on your health. It can ward off colds, decrease stress and prevent heart attacks. However, over the last number of years, there has been rising rates of sexually transmitted diseases proving that further education and awareness is required around the most common sexually transmitted diseases.

With today being National STIQ Day, we decided to discuss the three most common and infectious STIs, along with their symptoms.



Chlamydia is one of the most common STIs detected across the UK, with over 200,000 positive diagnosis recorded in 2016. However, what is concerning with chlamydia is that many people who have the infection are asymptomatic (don’t experience symptoms). Which leads to the increased risk of the infection being spread to another individual and if left untreated, can cause pelvic inflammatory disease, ectopic pregnancy and infertility.

Chlamydia symptoms in women include abnormal vaginal discharge, bleeding between periods, painful periods, abdominal pain with fever, pain during sex, and pain when urinating. For men, symptoms can be small amounts of clear or cloudy discharge from the tip of the penis, painful urination, burning and itching around the opening of the penis, pain and swelling around the testicles.


Gonorrhea, sometimes referred to as the “clap”, is caused by a bacterium called Neisseria gonorrhoeae which can grow and multiply easily in the mucous membranes of the body. This STI is very infectious and is easily spread during sexual intercourse. Like chlamydia, not all people who are infected with gonorrhoea show symptoms, so knowing when to seek treatment can be tricky.

Symptoms in women can include, green/whitish discharge from the vagina, pelvic pain, burning when urinating and spotting after intercourse.

For men, symptoms can include green/whitish discharge from the penis, burning when urinating, painful or swollen testicles and swollen glands in the throat.


Many people think that syphilis is a medieval infection that has been eradicated, but this is completely false and has led to a false sense of security. It can cause serious health problems for both women and men if not diagnosed and treated. Syphilis is caused by bacteria that is passed on while having sex and with an infected person, it can be passed through vaginal, oral and anal sex. Troublingly, pregnant women with syphilis can give it to their baby, which can lead to the risk of stillbirth occurring, as well as a condition called congenital syphilis which is very dangerous for the baby.


There are three different stages to syphilis, primary syphilis, secondary syphilis and tertiary syphilis. Primary syphilis symptoms include infectious sores or ulcers around the genitals or mouth. It is spread through contact with these sores which typically last between 2 to 6 weeks. The symptoms of secondary syphilis include a non-itchy skin rash and sore throat lasting a few to several weeks. A person may also feel tired and experience headaches. Other symptoms include fever, weight loss, hair loss and joint pain. The primary and secondary stages are when there is a greater risk of passing the infection to other people.

The final stage, tertiary syphilis, is the most dangerous, affecting around a third of people who are not treated for syphilis in the earlier stages. Tertiary syphilis can cause damage to the brain, nerves, eyes, heart, bones, skin or blood vessels. This may lead to serious or even life-threatening conditions including stroke, heart disease, dementia, and can cause blindness.

Worryingly, people who are infected with syphilis are more likely to be infected with HIV, which can enter the body through any syphilis sores that start to bleed during sex.

Read: What Are The Most Common Symptoms Of STDs?

Written by Hannah Kingston | Approved by Medical Director Dominic Rowley