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.
Vaginal discharge is normal and varies throughout the menstrual cycle. The colour and consistency can change based on hormones, health and sometimes infections. Most discharge is nothing to worry about, but some colours and patterns can point to specific conditions that need treatment. Here’s a practical guide.
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Discharge Colour Guide
| Colour | Likely Cause |
|---|---|
| Clear or milky white | Usually normal; can vary with cycle |
| Thick, white, clumpy | Yeast infection (thrush) |
| Thin, greyish-white with fishy smell | Bacterial vaginosis (BV) |
| Yellow | Can be normal; may indicate infection if with other symptoms |
| Yellow-green, frothy, smelly | Trichomoniasis |
| Green | Often Trichomoniasis; possibly gonorrhoea |
| Brown | Old blood; end of period; sometimes implantation bleeding |
| Pink or red | Fresh blood — can be period, spotting or post-sex bleeding |
Normal Discharge
Normal vaginal discharge:
- Clear, milky white or pale yellow
- Small amounts daily
- Varies with menstrual cycle (more around ovulation, sometimes stretchy and clear)
- Mild or no smell
- No itching, burning or pain
White Discharge
Mild, milky white discharge is usually normal. Thick, white, cottage-cheese-like discharge with intense itching is typical of yeast infection (thrush). Treatment is usually an antifungal tablet or cream.
Yellow Discharge
Yellow discharge can be normal (especially when it dries on underwear), but if accompanied by:
- Strong smell
- Itching or burning
- Pain during sex
- Abnormal bleeding
…it may indicate an STI like chlamydia, gonorrhoea or trichomoniasis. Get tested.
Green Discharge
Green discharge is not normal and usually indicates infection. Trichomoniasis classically causes frothy yellow-green discharge with a foul smell. Gonorrhoea can sometimes cause greenish discharge. Both need antibiotic treatment.
Brown Discharge
Brown discharge is usually just old blood. Common causes include:
- Start or end of a period
- Spotting mid-cycle
- Implantation bleeding (early pregnancy)
- Hormonal contraception changes
- After sex, particularly with cervical irritation
Persistent brown discharge, bleeding between periods or after sex should be checked, particularly for chlamydia, cervical issues or other conditions.
When to See a Doctor
- Unusual smell, especially fishy or foul
- Itching, burning or soreness
- Pain during sex
- Bleeding between periods or after sex
- Pelvic pain
- Green or frothy discharge
- Symptoms that don’t settle
Testing
- Swab from the vagina (self-collected or by a clinician)
- Test for chlamydia, gonorrhoea, trichomoniasis
- BV and yeast can be diagnosed from vaginal pH and microscopy
- Home kits are available for common STIs
Read more: STI discharge | Vaginal infections | Yeast infection smell
Frequently Asked Questions
Is brown discharge a sign of infection?
Usually not. Brown discharge is typically just old blood from the menstrual cycle. Persistent or unusual bleeding warrants investigation.
Why is my discharge green?
Green discharge often indicates trichomoniasis or another infection. See a clinician for testing and treatment.
Can my discharge change throughout the month?
Yes — normal discharge varies with your cycle. Changes in amount, consistency and colour are often hormonal rather than infection-related.
Related reading
- Common STI Symptoms in Women
- How Different STIs Affect Vaginal Discharge
- What Are Vaginal Bumps? Causes and When to Worry
- Abnormal Genital Discharge and Chlamydia
- Asymptomatic STIs: Silent Infections Explained
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.
