Leucorrhoea is the medical term for vaginal discharge, both the normal kind your body produces every day and the abnormal kind that signals an infection or other problem. Nearly every woman experiences it. In one large survey of adolescent females, 85% reported abnormal vaginal discharge at some point in their lives. The key isn’t whether you have discharge, but whether what you’re seeing is physiological (healthy and expected) or pathological (a sign something needs attention).
What Normal Discharge Looks Like
Healthy vaginal discharge is a mix of fluid that seeps through the vaginal walls, secretions from glands in the cervix, and skin cells that the vaginal lining constantly sheds. It is typically clear to white, doesn’t stick to the vaginal walls, and has no strong or offensive odor. Under lab conditions, normal discharge has an acidic pH below 4.5, which helps keep harmful bacteria in check.
The amount and texture shift throughout your menstrual cycle because they’re driven by hormone levels. In the days after your period, discharge tends to be dry or pasty. As ovulation approaches, rising estrogen makes it wetter, stretchier, and slippery, often compared to raw egg whites. After ovulation, it thickens or dries up again. If you’re on hormonal birth control, pregnant, or breastfeeding, you may notice different patterns altogether. During pregnancy, your body ramps up discharge production as an extra barrier against infections traveling toward the uterus.
Why Estrogen Matters
Estrogen is the main hormone behind leucorrhoea. It acts on receptors in the vaginal wall to keep the tissue thick, moist, and well-supplied with blood. In a woman of reproductive age, the vaginal wall measures about 2 to 3 mm thick, but it thins noticeably when estrogen drops, such as during menopause or while breastfeeding. Estrogen also promotes the production of glycogen in vaginal cells. When those cells shed naturally, beneficial bacteria feed on the glycogen and produce lactic acid, maintaining the acidic environment that wards off infection.
This is why discharge increases at predictable times: puberty (when estrogen first rises), ovulation (when estrogen peaks mid-cycle), pregnancy (when estrogen stays elevated for months), and sometimes with oral contraceptives. All of these represent physiological leucorrhoea and are completely normal.
When Discharge Becomes Abnormal
Pathological leucorrhoea looks, smells, or feels different from what your body normally produces. The three infections most commonly responsible are bacterial vaginosis, yeast infections (candidiasis), and trichomoniasis. Each produces a distinct type of discharge:
- Bacterial vaginosis (BV): Caused by an overgrowth of anaerobic bacteria that replace the normal vaginal flora. Discharge is typically thin, grayish-white, and has a noticeable fishy odor, especially after sex.
- Yeast infection (candidiasis): Caused by an overgrowth of Candida, a fungus that normally lives in the vagina in small numbers. Discharge is thick, white, and often described as cottage cheese-like. Itching and burning are the hallmark symptoms.
- Trichomoniasis: A sexually transmitted infection caused by a parasite. Discharge tends to be frothy, yellow-green, and foul-smelling, often accompanied by irritation and discomfort during urination.
Other possible causes of abnormal discharge include sexually transmitted infections like chlamydia and gonorrhea, cervical inflammation, foreign bodies (like a retained tampon), and, less commonly, cervical or vaginal growths. Yellow, green, or gray discharge, a strong or foul odor, and accompanying symptoms like itching, burning, or pelvic pain are all signals that something beyond normal physiology is going on.
How It’s Diagnosed
You can’t reliably diagnose the cause of abnormal discharge based on appearance alone, even though the color and texture offer clues. A proper evaluation typically combines several steps. Vaginal pH is measured using a simple test strip (home kits are available, though they only tell you if pH is elevated, not the specific cause). A pH above 4.5 suggests BV or trichomoniasis, while yeast infections usually keep pH in the normal acidic range.
In a clinical setting, a sample of discharge is examined under a microscope. A saline preparation can reveal the moving parasites of trichomoniasis or “clue cells,” epithelial cells coated in bacteria characteristic of BV. A second preparation using a potassium hydroxide solution makes yeast structures easier to spot. An “amine” or “whiff” test checks whether the discharge produces a fishy smell when exposed to the solution, another indicator of BV. Culture and more specialized tests may follow when results are unclear.
Treatment for Common Causes
Treatment depends entirely on the underlying cause, which is why getting the right diagnosis matters more than guessing.
For yeast infections, antifungal creams and suppositories are available over the counter and clear symptoms in 80% to 90% of women who complete a full course. Options range from a single-day suppository to a 7-day cream regimen. A single-dose oral antifungal pill is also available by prescription and works equally well for most women. Severe or recurring yeast infections may need a longer initial treatment followed by weekly oral antifungals for up to six months.
Bacterial vaginosis and trichomoniasis both require prescription antibiotics. BV is treated with oral or vaginal antibiotics, while trichomoniasis requires oral medication, and sexual partners need treatment at the same time to prevent reinfection.
Physiological leucorrhoea, the normal kind, doesn’t need treatment at all. If the volume feels excessive but there’s no odor, color change, or irritation, it’s almost certainly hormonal and harmless.
Risks of Ignoring Abnormal Discharge
Despite how common abnormal discharge is, fewer than half of young women in surveys seek medical care for it. That’s a problem because untreated vaginal infections can progress. BV and sexually transmitted infections, if left alone, can ascend into the uterus and fallopian tubes, leading to pelvic inflammatory disease. PID can cause chronic pelvic pain, scarring of the reproductive tract, and difficulty getting pregnant. During pregnancy, untreated BV raises the risk of preterm delivery and low birth weight. Trichomoniasis also increases susceptibility to other sexually transmitted infections, including HIV.
Hygiene Practices That Help
The vagina is self-cleaning, and many common hygiene habits actually do more harm than good. Douching disrupts the natural bacterial balance and is consistently linked to higher rates of BV. Scented soaps, sprays, and wipes in the genital area can irritate the vaginal lining and shift pH. Wearing breathable cotton underwear and avoiding prolonged time in wet swimwear or sweaty workout clothes helps keep moisture levels in check, since yeast thrives in warm, damp environments.
Wiping front to back after using the toilet reduces the chance of introducing intestinal bacteria into the vagina. During sex, condoms lower the risk of sexually transmitted infections that cause pathological discharge. Probiotics, particularly those containing Lactobacillus strains, are being studied for vaginal health, but evidence is still mixed on whether supplements meaningfully prevent infections.