Vaginal Infections

Vaginal infection is inflammation of the vagina and vulva caused by different factors, usually with discharge, itching, burning or odour. Common causes are bacterial vaginosis, vaginal thrush (vulvovaginal candidiasis) and trichomoniasis. Symptoms overlap, so symptoms alone cannot identify the cause; examination and testing are needed before appropriate treatment. This information is general and does not replace individual diagnosis or treatment advice.

How can normal discharge be distinguished from infection?

Vaginal discharge can vary in amount and consistency through the menstrual cycle in women of reproductive age. Beneficial bacteria called lactobacilli, which predominate in the vagina, help maintain its balance. Discharge alone does not mean infection.

The following may need assessment:

• A marked change in the amount, colour or smell of discharge from what is usual for you.
• Itching, burning, redness or swelling.
• Burning or pain during urination or sexual intercourse.

Colour or smell alone does not establish a diagnosis. The same appearance may have different causes, and different appearances may have the same cause.

What is bacterial vaginosis, and what symptoms can it cause?

In bacterial vaginosis, the balance of bacteria in the vagina changes, with other bacteria replacing lactobacilli. A thin, uniform discharge and a fishy smell are typical; itching may not be prominent. It may be associated with sexual activity, but whether it should be considered a conventional sexually transmitted infection is debated.

What is vaginal thrush (vulvovaginal candidiasis), and what symptoms can it cause?

Thrush results from overgrowth of Candida yeasts. Common symptoms include itching, burning and thick, curd-like discharge. These are not specific; other causes may produce similar symptoms. Yeast in a vaginal sample without symptoms does not by itself require treatment.

Thrush may develop more easily in some people with factors such as diabetes, conditions that suppress the immune system, corticosteroid use or recent antibiotic use.

What is trichomoniasis, and what symptoms can it cause?

Trichomoniasis is a sexually transmitted infection caused by a parasite. It may cause frothy or greenish discharge, an unpleasant smell, itching and burning when passing urine; some people have no symptoms. Diagnosis generally uses a laboratory test. Separate assessment for other infections that may occur alongside it may be considered.

Are discharge and itching always caused by infection?

No. Irritation or allergy from soap, perfumed products or pantyliners, thinning tissue after menopause and some skin conditions may cause similar symptoms. Persistent symptoms therefore require reassessment.

How is a vaginal infection diagnosed?

Assessment starts with symptoms and history. Your doctor examines discharge and vaginal tissue; vaginal acidity (pH) is usually measured and a discharge sample examined under a microscope. Culture or molecular tests may be requested if needed. Pap testing is not recommended for bacterial vaginosis; it screens cervical cells and is not used to diagnose vaginitis.

Discharge may also require consideration of a sexually transmitted infection. This assessment is made without judgement and according to medical need.

How are vaginal infections treated?

Treatment varies with the cause, so the same medicine is not suitable for every type of discharge.

• Bacterial vaginosis: Symptomatic people are treated with antibacterial medicines, taken by mouth or used vaginally.
• Vaginal thrush: In uncomplicated cases, azole antifungals are used as vaginal creams or pessaries, or taken by mouth.
• Trichomoniasis: Treatment uses an oral antiparasitic medicine, and the sexual partner must be treated at the same time.

Your doctor determines the medicine, dose and duration according to your circumstances, pregnancy and other conditions. Options and availability may differ by country. Follow your doctor's and leaflet's advice about alcohol and intercourse during treatment.

Can I use over-the-counter creams myself?

This is not recommended. Using creams without a diagnosis may result in incorrect treatment, masked symptoms and delayed diagnosis. Even with a previous thrush diagnosis, the same symptoms should not automatically be attributed to the same cause again.

Does my partner need treatment too?

• Bacterial vaginosis: Routine partner treatment has not been shown to reduce recurrence and is generally not recommended.
• Vaginal thrush: Routine partner treatment is not recommended. If a male partner has symptoms such as itching or redness of the glans and foreskin, this is assessed separately.
• Trichomoniasis: All sexual partners need treatment at the same time; otherwise, reinfection is common.

Why can vaginal infection recur?

There may be several reasons: incorrect or incomplete treatment through self-treatment, yeast species that respond less well to treatment, accompanying conditions such as diabetes, recent antibiotic use, reinfection from a partner in trichomoniasis, or symptoms actually having another cause.

How is recurrent vaginal infection assessed?

Recurrent vaginal thrush is generally defined as three or more symptomatic episodes within a year. Criteria may vary between sources and countries. Culture or similar tests may be requested to identify the yeast species, because some species may not respond to usual treatment. Treatment generally starts with a longer initial course and may be followed by a suppressive programme lasting months. Recurrent bacterial vaginosis may also prompt retreatment and longer-term suppressive approaches. These programmes are individual and planned by a doctor; benefits may not persist after medication stops.

Evidence for approaches such as probiotics, boric acid, vinegar or tea tree oil is limited. They cannot be said to be effective, and a doctor should be consulted before use.

How is vaginal infection assessed during pregnancy?

Tell your doctor about discharge during pregnancy. Medicines are selected for pregnancy suitability; for example, vaginal antifungals are generally preferred for thrush, while oral antifungals are generally not preferred. Symptomatic bacterial vaginosis is treated. Do not wait for an appointment if discharge is accompanied by bleeding, abdominal pain or fever during pregnancy.

What everyday steps may help prevent vaginal infections?

• Avoid vaginal douching, which may disrupt the vagina's natural balance.
• Avoid perfumed genital soaps, sprays and similar products; choose plain products.
• Wear cotton underwear and avoid remaining in wet clothing for long periods.
• If you have diabetes, blood glucose control may matter for thrush.
• Barrier methods during intercourse help reduce the risk of transmissible infections.

The level of evidence differs for each measure; they cannot be said to provide certain protection.

When is an appointment for assessment recommended?

Arrange assessment for discharge or itching that persists despite treatment or recurs frequently, bleeding after intercourse, or first-time symptoms with no clear cause.