Sexually Transmitted Infections (STIs)

Sexually transmitted infections are infections that can be passed through sexual contact. They can affect people of any age and often cause no symptoms at all. Many STIs are simple to detect with modern tests, and early assessment helps prevent complications and reduces the chance of passing infections to others.

These articles are intended as educational sources, not diagnostic nor taking place of a proper medical assessment. If you need help, please book an appointment with one of our GP’s.

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What an STI Is

STIs are infections that spread through vaginal, anal or oral sexual contact. Some are caused by bacteria, others by viruses or, less commonly, parasites. They can affect:

the genitals
throat or mouth
rectum
urinary tract
skin around the groin

Many STIs cause mild symptoms or none at all. This is why regular testing is recommended for anyone who is sexually active, especially after new partners.

Common Symptoms of STIs

You may experience:

Burning or discomfort when passing urine
Genital discharge
Itching or irritation
Genital sores, ulcers or small blisters
Pelvic or lower abdominal pain
Testicular discomfort
Bleeding after sex
Rectal discomfort or discharge

Many people have no symptoms, but can still carry and pass on infections.

Common Reasons to Get Reviewed or Tested

Speak to a GP or sexual health clinician if you have:

Have had unprotected sex with a new partner
Have symptoms that concern you
Have discharge or discomfort
Notice sores, ulcers or blisters
Have pelvic, lower abdominal or testicular pain
Have a partner who has symptoms
Want routine screening for reassurance
Are planning pregnancy
Have had a known STI exposure

Testing is simple and usually involves a urine sample, swab or blood test depending on symptoms and exposure.

Severe Symptoms – Seek Urgent Help

Seek urgent medical care if you develop:

Severe pelvic or lower abdominal pain
High fever or feeling very unwell
Severe testicular pain or swelling
Painful widespread rash
Eye redness with discharge after STI exposure
Confusion, severe headache or neck stiffness
Rapidly worsening symptoms

These signs may indicate a more serious infection that needs urgent assessment.

Understanding Typical Symptom Patterns

Bacterial STIs

Symptoms may include:

burning on urination
discharge
pelvic or testicular discomfort

Many people have no symptoms but still benefit from testing and treatment.

Viral STIs

May cause:

small blisters or clusters of spots
ulcers
recurrent symptoms
symptoms that come and go

Some viral STIs can remain in the body and flare from time to time.

STIs with no symptoms

Some infections are commonly silent:

chlamydia
gonorrhoea
HPV
certain viral infections

This is why regular testing is recommended.

STIs affecting the throat or rectum

These may not cause symptoms at all. Specific testing is usually required based on risk and exposure.

A GP can advise on the most appropriate tests depending on your history.

Common Organisms in Sexually Transmitted Infections

These organisms are associated with sexually transmitted infections. The table is for general understanding only and does not replace testing or medical assessment.

Type	Organism	Notes
Bacterial	Chlamydia trachomatis	Very common and often causes no symptoms. Can affect genitals, throat or rectum.
Bacterial	Neisseria gonorrhoeae	Can cause discharge or discomfort. Throat and rectal infection may be symptom free.
Bacterial	Mycoplasma genitalium	Can cause persistent urinary or pelvic symptoms in some cases.
Viral	Herpes simplex virus	Causes small painful blisters or ulcers which may recur.
Viral	Human papillomavirus (HPV)	Some types can cause genital warts. Others may affect cervical screening results.
Viral	HIV	Early infection may cause flu-like symptoms. Testing is recommended after risk exposure.
Viral	Hepatitis B and C	Can be sexually transmitted. May not cause symptoms in the early stages.

Partner Notification and Contact Tracing

If an STI is diagnosed, a GP or sexual health clinician may talk to you about letting recent partners know so they can be tested. This process is confidential and designed to prevent reinfection and reduce the spread of STIs.
Your clinician can discuss practical ways to approach this and, if needed, can help notify partners anonymously through specialist services.