Vaginal Infections: Bacterial Vaginosis and Yeast

The two most common causes of vaginal itching, odour and discharge are bacterial vaginosis (BV) and yeast infection, also called thrush. They can feel alike, but they are different problems and need different treatment.

This guide shows how to tell them apart, what causes them, how a doctor treats them, and how to lower the chance of repeat episodes.

Why the Vagina Gets Out of Balance

A healthy vagina holds a mix of helpful bacteria. When that balance shifts, other germs can overgrow. The CDC explains that in BV, the normal protective bacteria are replaced by high numbers of other bacteria. In thrush, a fungus called candida, which normally lives harmlessly on the body, grows too much in warm, moist conditions, according to the NHS.

Bacterial Vaginosis: Symptoms and Causes

Many people with BV have no symptoms at all; the NHS says about half of women with BV notice nothing. When symptoms appear, they usually include:

• Thin discharge that looks grey or white
• A strong fishy smell, often stronger after sex
• Sometimes burning when passing urine or itching outside the vagina (the NHS says BV usually does not cause itching, while the CDC lists it as possible, so itching alone does not settle the question)

The exact cause is not fully known. The NHS and CDC list these as raising the chance: new or multiple sex partners, not using condoms, douching, perfumed products used in or around the vagina, and having a coil (IUD). BV is not classed as a sexually transmitted infection, and it can occur in women who have never had sex. It cannot be caught from toilet seats, bedding or swimming pools.

Yeast Infection (Thrush): Symptoms and Causes

The NHS describes these signs:

• Thick white discharge, often like cottage cheese, usually without a smell
• Itching and irritation around the vagina and vulva
• Soreness or stinging during sex or when passing urine

Triggers include antibiotics, poorly controlled diabetes, a weakened immune system, hormone therapy, pregnancy and irritated skin. Thrush is not classed as an STI.

BV vs Thrush at a Glance

• Smell: BV has a fishy odour; thrush usually has none
• Discharge: BV is thin and grey-white; thrush is thick and white
• Itching: common in thrush; usually not a feature of BV
• Treatment: BV needs antibiotics; thrush needs antifungal medicine

Because the signs overlap with other infections, including trichomoniasis and others spread through sex, guessing is unreliable. Our guide to white discharge: normal or infection explains more patterns.

How Doctors Diagnose and Treat Them

The CDC says that history alone is not enough. A doctor will examine you and may test the discharge. Treatment then depends on the cause:

• BV: your doctor may prescribe antibiotics as tablets, gel or cream. Finish the whole course even if you feel better. Male partners usually do not need treatment, but a female partner may.
• Thrush: your doctor or pharmacist may advise antifungal medicine as a tablet, vaginal pessary or cream. The NHS says symptoms should clear within 7 to 14 days, and partners only need treatment if they have symptoms.

When to be cautious: Antifungal creams can damage condoms and diaphragms, so contraception may not be reliable during treatment. Ask your doctor or pharmacist for advice. Never share or reuse old prescriptions.

Why They Keep Coming Back

BV often returns within a few months, the NHS says. If it comes back more than four times a year, your doctor may suggest a longer course of treatment and look for triggers such as sex or periods. Thrush that returns more than four times in 12 months may need longer treatment, up to six months, as the NHS describes, and a check for causes like diabetes.

Tip: Note the dates of each episode, what you were taking, and where you were in your cycle. Patterns often point to a trigger your doctor can address.

Prevention and Self-Care

• Wash the outer genital area with water, and a plain unperfumed soap if you like; avoid washing inside
• Avoid perfumed soaps, bubble bath, deodorants, scented wipes and douching
• Wear cotton underwear and avoid tight clothing that traps moisture; dry well after washing
• Use condoms, which the CDC lists as a way to lower BV risk
• If you smoke, stopping may help, as the NHS notes for BV
• Keep diabetes well controlled, since high sugar can trigger thrush

What to Expect at the Clinic

Your doctor will ask when the symptoms began, what the discharge looks like, whether you have itching or pain, and whether you use any washes or take antibiotics. An examination follows, and a swab may be taken. The CDC notes that women with BV should also be offered testing for other infections, because the symptoms overlap.

It is fine to ask about anything, including sex and contraception. Doctors treat these problems every day, and honest answers lead to the right treatment. If symptoms continue despite treatment, ask whether a specialist opinion would help.

Infections in Pregnancy

Both conditions can happen in pregnancy. The NHS says BV carries a small risk of premature birth or miscarriage, though most pregnancies are unaffected, and treatment is recommended. Tell your doctor at your antenatal visit if you notice itching or a change in discharge, and do not use any medicine without advice. Untreated BV can also raise the chance of other infections, including pelvic infection; read about pelvic inflammatory disease.

When to See a Doctor

• It is your first time with these symptoms
• Symptoms do not clear after treatment, or keep returning
• You are pregnant or breastfeeding
• You have diabetes or a weak immune system
• You have pelvic pain, fever, bleeding between periods or after sex, or green or frothy discharge
• You may have been exposed to a sexually transmitted infection

For regular care and screening, see why regular gynecological check-ups matter.

Talk to a doctor

Book an appointment at Chaitanya Hospital, Kadapa (near RTC Bus Stand, Simhapuri Colony), or call +91 944 103 0587. Teleconsultation is also available if you would like to start with a conversation from home. This article is for general awareness and is not a substitute for a doctor's advice.