Medically reviewed guide · Last updated: 1 September 2026 · Reading time: approx. 10 min

Vaginal Discharge: What Colour and Smell Tell You — and When It Needs Checking

The most common causes compared

The causes in detail

Normal discharge: the vagina's self-cleaning system

The lining of the vagina and the cervix constantly produce a little fluid; together with shed cells this forms normal discharge (fluor vaginalis). Lactic acid bacteria (lactobacilli) keep the environment acidic — in women of reproductive age the pH is normally somewhere between 3.8 and 4.5. Amount and consistency follow the cycle: around ovulation plentiful, clear and stretchy like raw egg white, creamier in the second half of the cycle. Once it has dried on a panty liner, normal discharge often looks slightly yellowish. What matters is the change: a new smell, a new colour, itching, burning or pain.

Bacterial vaginosis: grey, thin and fishy

In bacterial vaginosis, one of the most common causes of unusual discharge in women of childbearing age, the lactic acid bacteria are pushed out by other bacteria such as Gardnerella. Typical is a thin, greyish-white discharge with a fishy smell that becomes more noticeable after sex or during your period. Itching is often absent. Vaginal douching, changing partners and smoking make it more likely. It is usually treated with an antibiotic as tablets or a vaginal gel — the practice decides which. To be honest: relapses are common. Newer study data suggest that treating the partner at the same time can reduce relapses in couples in a steady relationship; raise this if your vaginosis keeps coming back. In pregnancy vaginosis is associated with an increased risk of premature birth — so unusual discharge then always needs to be seen at the practice.

Vaginal thrush: white, crumbly and itchy

A yeast infection (vulvovaginal candidiasis), usually caused by Candida albicans, shows itself with a whitish, crumbly discharge like cottage cheese that hardly smells. The main symptoms are severe itching, burning, redness and pain during sex. Typical triggers are antibiotics, high oestrogen levels, poorly controlled diabetes or medicines that dampen the immune system. If thrush has already been confirmed by a doctor once and you clearly recognise the symptoms, an over-the-counter product such as clotrimazole is an option. The first time, in pregnancy, with relapses or if there is no clear improvement after a few days, the diagnosis belongs in the practice. For several episodes a year (from three or four, depending on the guideline) there are dedicated long-term treatment regimens.

Trichomoniasis: yellow-green and frothy

Trichomonads are sexually transmitted single-celled parasites. Typical is a plentiful, yellow-greenish, often frothy discharge with an unpleasant smell, together with burning and pain when passing urine — though some people who are infected notice hardly anything. It is treated with an antibiotic, and always together with sexual partners, otherwise the next infection follows.

Chlamydia and gonorrhoea: the silent infections

Chlamydia is considered the most common bacterial sexually transmitted infection in Germany and often goes unnoticed. If anything, a slightly yellowish discharge, bleeding between periods, bleeding after sex or burning when urinating may be noticeable; gonorrhoea can run a similar course. Left untreated, both can ascend into the womb and fallopian tubes and put fertility at risk. Women with statutory health insurance are entitled to an annual chlamydia screening by urine sample until their 25th birthday.

Oestrogen deficiency: scanty, watery and sensitive

During and after the menopause, while breastfeeding or on anti-hormonal treatment, the lining becomes thinner and the pH rises. Paradoxically, the vagina feels dry, yet a thin, watery-yellowish, sometimes slightly bloody discharge can still occur. More on this under vaginal dryness. Bloody discharge after the menopause, however, is always investigated first.

Bloody, brownish or foul-smelling

Brownish discharge just before or after a period is usually old blood; spotting also occurs on the pill or with a coil. Repeatedly bloody discharge or bleeding after sex, on the other hand, should be examined — behind it there may be polyps, inflammation of the cervix or, less commonly, cell changes up to and including cervical cancer. Very foul-smelling, brownish discharge can point to a forgotten tampon. And intimate sprays, perfumed washes, latex or spermicides irritate the lining.

Self-tests: first clues at home

These observations do not replace a diagnosis — thrush, vaginosis and trichomonas cannot be reliably told apart on appearance alone, and mixed infections do occur. But they help you judge how urgent it is.

• The colour and smell check: look at fresh discharge on a white panty liner. Severe itching without a smell points more to thrush, a fishy smell without much itching more to vaginosis, yellow-green and frothy more to trichomonas.
• The pH test from the pharmacy: a value up to 4.5 makes vaginosis and trichomonas less likely, though thrush remains possible. Above 4.5 points more towards vaginosis, trichomonas or oestrogen deficiency. Do not measure during your period, shortly after sex or after vaginal pessaries — that skews the result.
• The cycle check: more clear discharge around ovulation or brownish traces just before or after a period are something different from a new smell in the middle of the cycle.
• The medication review: an antibiotic, a new diabetes or hormonal product, cortisone in the last two weeks? Often the quickest lead to the cause.
• The accompanying signs check: fever, lower abdominal pain, pain during sex, bleeding outside your period or blisters in the genital area turn an observation into a doctor's appointment.

Warning signs: when not to wait

• Discharge with fever, lower abdominal pain or pain during sex
• Bloody or brownish discharge more than a year after your last period
• Repeated bleeding after sexual intercourse
• Unusual discharge, a sudden watery leak of fluid or bleeding during pregnancy
• Blisters, ulcers or painful sores in the genital area, for example with genital herpes
• Symptoms that persist despite treatment or keep coming back
• Discharge in girls before puberty

The treatment pathway: step by step

Without warning signs, the approach moves from simple to targeted investigation — with one ground rule: do not keep treating yourself on suspicion.

1. Normal or changed? More discharge without a smell, itching or pain needs no treatment.
2. Leave out irritants. Wash the intimate area with water only, no vaginal douches or intimate sprays, breathable underwear.
3. Self-treatment only for a familiar pattern. An antifungal from the pharmacy is appropriate if thrush was confirmed by a doctor in the past and the symptoms are the same. No clear improvement after a few days: it may not have been thrush after all.
4. Gynaecological examination. A speculum examination, a pH measurement and a drop of discharge under the microscope (wet mount) clarify a great deal during the appointment itself. If a sexually transmitted infection is suspected, the pathogen is tested for by PCR; for recurrent thrush, a fungal culture follows.
5. Treatment according to the cause. Antifungals or antibiotics, with partner treatment for sexually transmitted infections. The active substance, form and duration are always decided by the practice treating you. With relapses, blood sugar, the medication list and the method of contraception all need reviewing.

The medication angle: when treatment changes the vaginal environment

Many women get their first bout of thrush a few days after a course of antibiotics. That is the best-known link, but not the only one.

Antibiotics: the classic

Antibiotics such as amoxicillin or doxycycline also decimate the lactic acid bacteria in the vagina — they do not affect yeasts, which then have an easy time of it. That is no reason to stop a necessary treatment: finish it as prescribed, and mention when it is prescribed if you are prone to thrush. More in the guide Taking antibiotics correctly.

SGLT2 inhibitors and cortisone

Diabetes medicines such as dapagliflozin or empagliflozin remove sugar via the urine — a breeding ground for fungi. According to the summary of product characteristics, genital infections are among the common side effects, even when these medicines are prescribed for heart or kidney failure without diabetes. Cortisone tablets, immunosuppressants and chemotherapy weaken the immune defences and make yeast infections more likely and more stubborn. Do not stop them on your own initiative — with repeated infections, the practice decides.

Hormones: the pill, the coil, HRT and tamoxifen

An oestrogen-containing pill or hormone replacement therapy tends to make discharge more plentiful, and some women get yeast infections more often. The progestogen-only pill, the hormonal coil or an implant more often lead to spotting that colours the discharge brownish. Tamoxifen after breast cancer frequently causes increased discharge — but any bleeding on tamoxifen should be checked, because it can change the lining of the womb. Aromatase inhibitors, by contrast, tend to cause dryness.

Self-treatment and painkillers: the limits

Over-the-counter antifungals work well — if it is thrush. But self-diagnosed "thrush" is often wrong, and after vaginal creams a whitish residue often comes away that looks like discharge. More on this under Limits of self-medication. Painkillers such as ibuprofen relieve lower abdominal pain but can mask an ascending infection: without medical advice, take them for no longer than three to four days in a row — and with a fever, get it checked first.

How to prevent unusual discharge

• Less is more with intimate hygiene — water is enough. Vaginal douches, intimate sprays and fragrances disturb the acidic environment.
• Condoms with new partners — they protect against chlamydia, gonorrhoea and trichomonas. If you are under 25, make use of the annual chlamydia screening.
• Air instead of plastic — cotton underwear, change out of wet swimwear promptly, no panty liners with a plastic backing all day, every day. The evidence is limited, but moist warmth encourages fungi.
• Keep an eye on blood sugar and antibiotics — with diabetes, well-controlled levels are the best protection against thrush; take antibiotics only when they are really needed.
• Go to your screening appointments — cervical cancer screening (a smear test every year from 20, from 35 a smear test plus an HPV test every three years) and HPV vaccination protect against cell changes.

Intimate health and medicines in view — with brite

Medication plan, dosing history and symptoms in one place. Free of charge.

Start for free