Do STDs Have a Smell? Understanding Vaginal Odour Changes, Syphilis & Other Infections

Do STDs Have a Smell? The Short Answer

Yes, some sexually transmitted infections can cause changes to vaginal odour, though not all do. While a healthy vagina has a natural, mild scent that varies throughout the menstrual cycle, a persistent, unusual, or particularly strong odour – especially when accompanied by discharge changes or other symptoms – can sometimes indicate an underlying infection.

Understanding what's normal for your body and recognising when changes might signal a problem is essential for maintaining your sexual health. Let's explore which STIs can affect vaginal odour, what other symptoms to watch for, and when testing is recommended.

What STDs Can Cause Vaginal Smell?

Not all STIs affect vaginal odour, but several common infections are known to produce distinctive changes:

Trichomoniasis: The Most Common Culprit

Trichomoniasis is the STI most strongly associated with vaginal odour changes:

• Strong, fishy odour that's often worse after sex
• Yellow-green, frothy discharge
• Vaginal itching and irritation
• Pain during urination or sex
• Up to 70% of cases are asymptomatic initially

Trichomoniasis is caused by a parasite and is highly treatable with antibiotics. If you're experiencing these symptoms, trichomoniasis testing can provide a definitive diagnosis.

Chlamydia: Often Silent but Can Affect Discharge

Chlamydia is one of the most common STIs in the UK, and while it doesn't always cause a noticeable odour, it can:

• Produce unusual vaginal discharge that may have a mild odour
• Cause discharge that's yellow or cloudy
• Lead to pain during urination
• 70% of women experience no symptoms at all

Because chlamydia often has no symptoms, routine testing is essential for sexually active individuals. A chlamydia test is quick, painless, and provides reliable results.

Gonorrhoea: Foul-Smelling Discharge

Gonorrhoea can cause more noticeable changes:

• Unpleasant or foul-smelling discharge
• Yellow or green discharge
• Heavier discharge than usual
• Pelvic pain or discomfort
• Pain during urination

Like chlamydia, gonorrhoea can remain asymptomatic in many cases. If you notice these symptoms, gonorrhoea testing is recommended to prevent complications.

Bacterial Vaginosis (BV): Not an STI, But Often Related

While not technically an STI, bacterial vaginosis is worth mentioning because:

• It's the most common cause of vaginal odour
• Sexual activity can trigger BV episodes
• Produces a strong, fishy odour
• Causes thin, grey-white discharge
• Can occur alongside STIs

BV is caused by an imbalance in vaginal bacteria and is easily treatable. However, if you have BV symptoms, it's wise to also test for STIs, as they can occur together.

Syphilis: Indirect Effects on Odour

Syphilis doesn't typically cause vaginal odour changes in its early stages, but:

• Primary stage features a painless sore (chancre) that may go unnoticed
• Secondary stage can cause various symptoms including discharge
• The sores themselves may become infected, leading to odour
• Can be transmitted through contact with sores during sex

Early syphilis testing is crucial, as the infection progresses through stages and becomes more serious if left untreated.

What About Other STIs?

Some common STIs are less likely to cause odour changes:

• HIV: Doesn't directly cause vaginal odour, but can make you more susceptible to other infections
• Herpes: Causes sores rather than discharge changes
• HPV: Usually symptomless; doesn't typically affect vaginal odour
• Genital warts: Visible growths without odour changes

However, having one STI increases your risk of others, so comprehensive testing is always advisable.

Normal vs. Abnormal Vaginal Odour

It's important to understand what's normal before assuming something is wrong.

What's Normal

A healthy vagina has a natural scent that:

• Varies throughout your menstrual cycle
• May be slightly stronger during menstruation
• Can change with diet, hydration, or stress
• Is usually described as slightly musky or mild
• Intensifies with sweat or exercise

What's Concerning

Seek medical attention if you notice:

• Persistent fishy odour, especially after sex
• Unusually strong or foul smell that doesn't go away
• Odour accompanied by unusual discharge (colour, consistency, or amount)
• Vaginal itching, burning, or irritation
• Pelvic discomfort or pain during sex or urination
• Odour that persists despite good hygiene

When Should You Get Tested?

If you're experiencing changes in vaginal odour, STD testing in London is recommended in these situations:

Immediate Testing Recommended

• Persistent or strong vaginal odour with discharge changes
• New sexual partner, especially if unprotected sex occurred
• Partner has been diagnosed with an STI
• Odour accompanied by pain, itching, or burning

Routine Testing Recommended

• Annually for sexually active individuals
• Every 3-6 months if you have multiple partners
• Before starting a new relationship where you plan to stop using condoms
• After any unprotected sexual contact

How STI Testing Works

Modern STI testing is straightforward, confidential, and often painless:

Testing Methods

Swab tests:

• Quick and simple vaginal swab
• Can test for multiple infections simultaneously
• Often used for trichomoniasis, chlamydia, gonorrhoea

Urine tests:

• Non-invasive option for some STIs
• Effective for chlamydia and gonorrhoea

Blood tests:

• Used for HIV, syphilis, herpes
• Can detect infections even without symptoms

PCR testing:

• Highly accurate molecular testing
• Detects infection DNA/RNA
• Available in our full STI screening packages

What to Expect

1. Confidential consultation: Discuss your symptoms and concerns with a healthcare professional
2. Sample collection: Usually takes just a few minutes
3. Lab analysis: Most results available within 1-3 days
4. Results and treatment: If positive, treatment is prescribed immediately
5. Partner notification: Guidance on informing sexual partners

Treatment Options

The good news is that most STIs causing vaginal odour are highly treatable:

Bacterial Infections

• Trichomoniasis: Single-dose or short-course antibiotics
• Chlamydia: Typically 7 days of antibiotics
• Gonorrhoea: Injection plus oral antibiotics
• Bacterial vaginosis: Antibiotic tablets or gel

Important Treatment Notes

• Complete the full course of antibiotics even if symptoms improve
• Avoid sexual contact until treatment is finished and symptoms resolve
• Partners should be tested and treated if necessary
• Retest after treatment to ensure the infection has cleared

Common Causes of Vaginal Odour That Aren't STIs

Not every odour change indicates an infection. Other common causes include:

Hygiene and Lifestyle

• Retained tampons or menstrual products
• Tight, non-breathable clothing
• Excessive washing (disrupts natural pH balance)
• Scented products, douches, or feminine hygiene sprays
• Sweating or poor ventilation

Medical Conditions

• Bacterial vaginosis (most common non-STI cause)
• Yeast infections (thrush)
• Hormonal changes during menstruation, pregnancy, or menopause
• Certain medications, particularly antibiotics

When It's Not Serious

• Temporary changes after sex
• Menstrual cycle variations
• Diet changes (garlic, asparagus, etc.)
• Normal post-exercise sweating

How to Maintain Healthy Vaginal pH and Odour

Prevention is always better than treatment:

Do's

• Wear breathable cotton underwear
• Change out of wet swimwear or gym clothes promptly
• Wash with warm water and mild, unscented soap
• Wipe front to back after using the toilet
• Use condoms to reduce STI risk
• Maintain a balanced diet and stay hydrated

Don'ts

• Don't douche – it disrupts natural bacterial balance
• Avoid scented tampons, pads, or feminine hygiene products
• Don't use harsh soaps or cleansers inside the vagina
• Avoid wearing tight, synthetic underwear regularly
• Don't ignore persistent symptoms

Why Early Detection Matters

Ignoring changes in vaginal odour or delaying testing can lead to:

• Progression of infection to more serious stages
• Pelvic inflammatory disease (PID) which can cause infertility
• Increased risk of other STIs, including HIV
• Transmission to sexual partners
• Complications during pregnancy
• Chronic pelvic pain

Early testing and treatment prevent these complications and protect both your health and your partners'.

Frequently Asked Questions

Do all STDs cause a smell?

No, not all STDs cause noticeable vaginal odour. Trichomoniasis, gonorrhoea, and chlamydia are most likely to cause odour changes, while infections like HIV, herpes, and HPV typically don't affect vaginal smell.

What does trichomoniasis smell like?

Trichomoniasis typically causes a strong, fishy odour that may be more noticeable after sexual intercourse. The smell is often accompanied by yellow-green, frothy discharge.

Can syphilis cause vaginal odour?

Syphilis doesn't typically cause vaginal odour directly in its early stages. However, if syphilis sores become secondarily infected, they may produce an unpleasant smell. The primary symptom is a painless sore (chancre).

How soon after infection does odour appear?

This varies by infection. Trichomoniasis symptoms, including odour, may appear 5-28 days after exposure. Chlamydia and gonorrhoea can take 1-3 weeks. However, many STIs remain asymptomatic, which is why regular testing is essential.

Can you have an STD with odour but no discharge?

While less common, it's possible to experience odour changes without significant discharge, especially in early infection stages. Any persistent unusual odour warrants testing.

Will the smell go away after STI treatment?

Yes, if the odour is caused by an STI, it should resolve within a few days to weeks of starting appropriate antibiotic treatment. If odour persists after treatment, contact your healthcare provider for reassessment.

Is a fishy smell always an STI?

No, bacterial vaginosis (BV) is the most common cause of fishy vaginal odour and isn't sexually transmitted, though sexual activity can trigger it. However, BV and STIs can occur together, so testing is wise.

Take Control of Your Sexual Health

Changes in vaginal odour can understandably cause worry and embarrassment, but remember: vaginal odour changes are common, usually treatable, and nothing to feel ashamed about. Whether your symptoms indicate an STI or another condition, getting tested is the first step toward resolution.

Our private sexual health clinic provides confidential, non-judgemental testing with fast, accurate results and immediate treatment when needed. Don't let uncertainty or anxiety prevent you from getting the care you deserve.

Book your confidential STI test today and take the first step towards peace of mind and better sexual health.