References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
STI symptoms in women are frequently mild, easily confused with other conditions, or completely absent. Around 70% of women with chlamydia and up to 50% with gonorrhoea experience no symptoms at all. This is why regular testing matters more than watching for signs.
If you’ve noticed something unusual, whether it’s a change in discharge, pain during sex, bleeding between periods, or itching, this guide covers what each symptom could mean, which STIs to consider, and when to get tested.
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STI Symptom Checklist for Women
| Symptom | Possible STIs | Also Could Be |
|---|---|---|
| Unusual vaginal discharge (colour, smell, amount) | Chlamydia, gonorrhoea, trichomoniasis | Bacterial vaginosis, thrush |
| Pain or burning when urinating | Chlamydia, gonorrhoea, herpes | UTI, cystitis |
| Bleeding between periods or after sex | Chlamydia, gonorrhoea, cervical HPV changes | Hormonal changes, polyps |
| Pain during sex | Chlamydia, gonorrhoea, herpes, PID | Endometriosis, vaginismus |
| Lower abdominal or pelvic pain | PID (from chlamydia/gonorrhoea) | Ovarian cysts, menstrual cramps |
| Sores, blisters, or ulcers on genitals | Herpes, syphilis | Skin irritation, ingrown hair |
| Warts or bumps on genitals | HPV (genital warts) | Skin tags, Fordyce spots |
| Itching or irritation | Herpes, trichomoniasis, pubic lice | Thrush, dermatitis, allergic reaction |
| Sore throat (after oral sex) | Gonorrhoea, chlamydia | Cold, flu, strep throat |
| Rash (body) | Syphilis (secondary), HIV (acute) | Allergic reaction, viral rash |
Chlamydia Symptoms in Women
Chlamydia is the most commonly diagnosed STI in the UK, and women are disproportionately affected by its complications because it so often goes unnoticed.
When symptoms appear (in roughly 30% of cases), they include:
- Unusual vaginal discharge that may be watery or slightly discoloured
- Pain or burning when urinating
- Bleeding between periods or after sex
- Lower abdominal pain (if infection has spread to the uterus or tubes)
Untreated chlamydia can cause pelvic inflammatory disease (PID), which can lead to chronic pain, ectopic pregnancy, and infertility. This damage can happen without any obvious symptoms.
Treatment: azithromycin or doxycycline. Read more: What is chlamydia?
Gonorrhoea Symptoms in Women
Gonorrhoea often produces no symptoms in women, which is why it’s frequently called a “silent” infection. When symptoms do occur:
- Increased or unusual vaginal discharge (often thin, watery, yellow, or green)
- Pain when urinating
- Bleeding between periods
- Heavier periods
- Lower abdominal pain
Like chlamydia, untreated gonorrhoea can cause PID and fertility problems. Treatment requires an antibiotic injection (ceftriaxone).
Read more: What is gonorrhoea?
Genital Herpes Symptoms in Women
A first herpes outbreak in women can be more severe than in men. Symptoms may include:
- Tingling, itching, or burning in the genital area before blisters appear
- Small, painful blisters on the vulva, vagina, cervix, buttocks, or thighs
- Blisters that burst into shallow, painful ulcers
- Pain when urinating (if urine touches open sores)
- Flu-like symptoms, swollen glands, and fever during a first outbreak
- Vaginal discharge
Recurrent outbreaks are usually milder and shorter. Antiviral medication can manage symptoms.
Treatment: aciclovir or valaciclovir. Read more: Genital herpes
Syphilis Symptoms in Women
Syphilis symptoms progress through stages:
- Primary: A painless, round sore (chancre) on the vulva, vagina, cervix, or mouth. It can be internal and easy to miss. Heals in 3-6 weeks without treatment.
- Secondary: Rash (often on palms and soles), sore throat, swollen glands, patchy hair loss. Appears weeks after the chancre heals.
- Latent: No symptoms, but infection remains.
Syphilis is fully curable with penicillin at any stage. Read more: What is syphilis?
HPV Symptoms in Women
Most HPV infections cause no symptoms and clear on their own. When symptoms occur:
- Low-risk HPV: Genital warts (flesh-coloured bumps on the vulva, vagina, or anus)
- High-risk HPV: No symptoms. Detected through cervical screening. Can cause abnormal cell changes that, if untreated, may develop into cervical cancer over years.
Regular cervical screening (every 3-5 years from age 25) is the most important tool for catching HPV-related cervical changes early.
Trichomoniasis Symptoms in Women
Trichomoniasis is more likely to cause symptoms in women than men:
- Frothy, yellow-green vaginal discharge with a strong, unpleasant smell
- Itching, soreness, and redness around the vagina
- Pain during sex or urination
Treatment: metronidazole tablets. Read more: What is trichomoniasis?
When Is It Not an STI?
Many symptoms overlap with non-STI conditions:
- Thrush (candida): Thick, white, cottage-cheese-like discharge with itching. Very common and not sexually transmitted.
- Bacterial vaginosis (BV): Thin, greyish discharge with a fishy smell. Not an STI, caused by bacterial imbalance.
- UTI: Burning when urinating, frequent urination, cloudy urine. Caused by bacteria entering the urethra.
- Contact dermatitis: Itching and irritation from soaps, detergents, condoms, or lubricants.
The only way to distinguish between these conditions and STIs is testing. Don’t self-diagnose.
When to Get Tested
- Any new or unusual symptoms in the genital area
- After unprotected sex with a new partner
- If a partner has been diagnosed with an STI
- Annually if you’re sexually active and under 25 (NHS recommendation)
- Before starting a new sexual relationship
- If you’re pregnant (routine antenatal screening includes STI tests)
Order a discreet home STI test or find your nearest sexual health clinic.
Frequently Asked Questions
Can I have an STI with no symptoms at all?
Yes. This is very common. Chlamydia, gonorrhoea, HPV, trichomoniasis, and even HIV can all be present without causing any noticeable symptoms. Regular testing is the only reliable way to know your status.
Is unusual discharge always an STI?
No. Thrush, bacterial vaginosis, and hormonal changes can all cause discharge changes. But if the discharge is new, different from your normal, accompanied by smell or pain, or appeared after sex with a new partner, get tested to be safe.
Can a smear test detect STIs?
Cervical screening checks for HPV and abnormal cervical cells. It does not test for chlamydia, gonorrhoea, herpes, syphilis, or HIV. You need a separate STI test for those.
Should I get tested if I only have one partner?
If you haven’t been tested since becoming sexually active, yes. Your partner may have contracted an STI from a previous relationship without knowing. Many STIs are asymptomatic, so even long-term monogamous couples can carry undiagnosed infections.
Related reading
- Abnormal Genital Discharge and Chlamydia
- Asymptomatic STIs: Silent Infections Explained
- Causes of Painful Sex and How to Treat It
- Cold Sores vs Syphilis Sores: How to Tell the Difference
- Common STI Symptoms in Women
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
