At a Glance

  • STDs are on the increase with doctors warning of a sexual health epidemic.
  • Many STDs have no obvious signs or symptoms.
  • Regular testing can ensure infections are treated promptly, reducing the chances of any serious complications developing.
  • Chlamydia is the most common STD in the UK.
  • Sexual health clinics offer discrete and professional help, advice and treatment.


What is an STD/ STI and how are they transmitted?

Sexually transmitted diseases (STDs), also known as sexually transmitted infections (STIs), are passed through unprotected vaginal, anal or oral sex or through genital contact. They can also be passed through the sharing of sex toys.

Condoms are the most effective form of protection against transmission. Although they do not offer 100% certainty of protection against infections, they are very effective nevertheless.

STDs can be bacterial, viral or even parasitic in nature. Some doctors have warned of a sexual health epidemic if rising infection levels are not brought under control.

What should I look out for?

The term STI is increasingly being preferred over STD, as not all infections have symptoms, whereas most diseases do.

Although symptoms can vary depending on the infection, speak to your doctor if you experience any of the following:

  • Pain when urinating or having sex
  • Vaginal, penile or anal discharge or itching
  • Growths, lumps, blisters or sores around the genitals or anus
  • A rash around your genitals
  • Vaginal or anal bleeding

Where/how can I get tested?

Your GP can signpost you to a sexual health clinic, or you can check online for your local centre. Services at these clinics, including all STD tests and treatments, are usually free.

The clinics are obviously very discrete and you can remain anonymous if you want.

There are normally both male and female doctors or nurses present so there is no need to be embarrassed.

Home testing kits for some STDs, including chlamydia, are also now available to buy.  


The most common STD, and indeed one of the most common bacterial infection in the UK, it can cause serious complications if left untreated.  

Most prevalent in young adults, yearly testing is recommended. The only way to know for certain if you are infected is to be tested.  

Over half of all men and women with chlamydia have no symptoms. Often people can be infected for months or years without even realising, thereby infecting their partners unknowingly.  

When symptoms do occur, they commonly present as pain when passing urine, bleeding during or after sex, vaginal or penile discharge, lower abdominal pain in women and pain in the testicles.

Fortunately, the infection is easily treated by antibiotics. Without treatment, complications can include inflammation of the testicles, reactive arthritis, pelvic inflammatory disease in women and complications during pregnancy. It can even cause infertility.


The second most common STD and as with chlamydia there are often no signs or symptoms of infection.

In women, gonorrhea can cause a thin or watery, yellow or green vaginal discharge. There can be pain when urinating along with lower abdominal pain. It can cause bleeding outwith periods or make period bleeding heavier. The infection can also be passed from mother to child during childbirth, which can in rare cases lead to blindness in the newborn.

In men, a white, yellow or green discharge from the penis can occur, along with pain in passing urine and possibly even discomfort in the testicles.

Treatment is normally very successful, with an antibiotic injection and tablets given on the same day. Symptoms usually start improving within a few days. A follow-up test is arranged after a week or two to make sure the infection is completely gone.


Although not as common as chlamydia or gonorrhea, as per most STDs it can cause serious health problems if left untreated.

Syphilis symptoms tend to come in stages and are similar for men and women. As the symptoms can come and go, or change over time, recognising them can be difficult. These stages are known as the primary, secondary and tertiary stages of syphilis.

Primary symptoms include ulcers or sores that can appear anywhere on the body, but normally on the vagina, penis or around the anus. A person can also develop swollen glands in the neck, armpits or groin.

These primary symptoms normally pass after 2 – 8 weeks, but if left untreated can progress on to the secondary stage.

The secondary stage symptoms can consist of a blotchy, non itchy rash that can appear anywhere on the body, but often on the palms of the hands or soles of the feet. Small flat warts can appear on the vulva or around the anus. There may be a flu-like illness with loss of appetite and swollen glands, which can last for several weeks. It can also cause white patches to appear in the mouth.

These symptoms can come and go for several months. If the infection still remains untreated, it often enters a ‘latent’ symptomless stage which is still contagious. The infection can remain in this state for several decades.

Eventually, it can spread to the brain and nerves causing serious health complications. These include meningitis, stroke, blindness and even dementia symptoms, however, this tertiary stage is very rare in the UK.

Although still treatable at this stage, it might not be possible to reverse any damage that has already occurred.

Genital warts

The most common viral STD, genital warts are caused by the human papilloma virus (HPV). Not everyone who has the virus develops warts, and the body tends to clear the infection over time. Long-term health complications are very unlikely.

If warts do appear, this can happen many months, even years after coming into contact with the virus. They normally present as small growths, lumps or skin changes around the genitals or anus, although they can sometimes grow larger in size.  

They can appear on their own or in groups, and are normally painless.  Internal warts in the urethra can sometimes cause a person’s pee flow to become distorted.

Treatment normally consists of the application of a wart cream or liquid over a several week period.  Freezing and laser treatments are now increasingly being used. In rare occasions, a small surgical procedure may be needed to remove the wart(s).  

The HPV which causes genital warts does not cause cancer, however, some other sexually transmitted HPVs have been linked to cervical cancer in women.

The HPV vaccine offered to girls in the UK protects against this cancer and also the type of HPV which causes genital warts.

Genital Herpes

Caused by the herpes simplex virus, most people do not have any symptoms. Indeed, if the symptoms do occur, they can present months or years after having been infected with the virus.

Being the same virus which causes cold-sores around the mouth, initially a flu-like illness can occur, with fever, tiredness and aches, followed by a tingling, burning or itching feeling around the genital or anal area.  

Small, fluid-filled blisters can develop around the genitals, anus, upper thighs or buttocks. There may be some discharge or pain when urinating.

Although there is no cure, symptoms normally clear up themselves. Antivirals are sometimes prescribed to help shorten an outbreak.

Once cleared up, recurrences can occur, although the first episode is normally the most severe. Recurrent outbreaks are usually milder and increasingly infrequent.


Caused by a tiny parasite called Trichomonas vaginalis (TV), symptoms usually develop within a month of becoming infected. These symptoms are very similar to other STDs so diagnoses without a test can be difficult.

Unlike some other STDs, it can be cured, normally by a short antibiotic course.  

For women, symptoms include soreness, inflammation or itching in or around the vagina. A greeny-yellow frothy discharge can occur, which can smell unpleasant. There may be some abdominal pain and discomfort passing urine.

For men, a discharge from the penis is common with a soreness when passing urine also possible.

As per other STDs there can be complications, particularly during pregnancy so prompt diagnosis and treatment is essential. It is important that any sexual partners are treated at the same time, even if they are not showing any symptoms of infection.


Perhaps the most stigmatised of all STDs, the Human Immunodeficiency Virus (HIV) remains in the body for life. Although it cannot be cured, modern treatments have resulted in HIV positive patients living long, relatively normal lives.

Soon after becoming infected, ‘seroconversion’ illness can occur with flu-like symptoms such as fever, headaches, tiredness and sore throat. After these symptoms have passed, many HIV positive people will live for years without any symptoms- often unaware of their HIV positive status.  

Without treatment, over time the virus attacks and weakens the immune system, leaving a person more susceptible to serious illnesses and infections. This weakened immune system is termed AIDS- acquired immune deficiency syndrome.

It is for this reason that early diagnosis is essential. Medicines can help keep the viral load of HIV in a person’s blood very low, thereby preventing damage to the immune system.

Pubic Lice (crabs)

Normally spread through close bodily contact, these tiny insects are found in pubic hair, as well as other body hair. Unlike head lice, they do not live in the scalp.

A range of treatments, including creams and shampoos, can be used to clear a pubic lice infestation. Normally these treatments are repeated after 7 days to ensure that all the lice have been eradicated.

The number of sexually transmitted diseases diagnosed every year remains worryingly high. The fact that young people are disproportionately affected by these infections underlines the need for adequate sexual health and relationship advice tailored towards this susceptible group. The common STDs briefly described in this article represent the tip of the iceberg, with the emergence of new and resistant infections a real concern for the future. Early diagnosis of infection and the promotion of safe sex practices are vital if we are to break this worrying trend.