Vaginal thrush, also known as vaginal candidiasis, is an infection caused by a fungus (yeast) called Candida albicans. Vaginal thrush is sometimes referred to as a yeast infection. Candida albicans is present naturally in the intestines and vagina but in certain circumstances overgrowth of the organism may occur causing an infection. Thrush is not a sexually transmitted infection (STI) but it can be passed on to a sexual partner.
What are the symptoms of thrush?
All women have a natural vaginal discharge. If there are any changes in the nature of the normal discharge an infection may be present. The first time a woman has thrush she will normally seek medical advice to confirm that it is in fact thrush and not another type of vaginal infection. Some women suffer from recurrent thrush and learn to recognise the start of symptoms very quickly.
There is usually a thick, white discharge which is often described as resembling cottage cheese. The discharge caused by thrush should not smell and should not change colour - if it smells or changes colour this may indicate a different type of infection. The discharge may become quite heavy and can cause severe vulval itching. The vulva may become inflamed and swollen. Sexual intercourse can be very uncomfortable and it may hurt to pass urine. Although it is not a serious condition, thrush can be very uncomfortable and needs treatment.
What causes thrush?
Thrush occurs when the normal balance between the micro-organisms naturally found in the vagina is disturbed. An imbalance can be triggered by a number of things and some women are more prone to developing thrush than others. Some antibiotics can kill the "friendly" bacteria as well as the harmful bacteria for which they have been prescribed. The "friendly" bacteria maintain an acidic environment in the vagina which prevents Candida albicans from multiplying. When the balance becomes upset, for example, by antibiotics, the fungus is able to multiply and thrush develops. Some women may need to take a course of antifungal treatment whenever they have to take antibiotics to prevent thrush from occurring.
The normal balance of micro-organisms in the vagina can also be upset during pregnancy as a result of the increase in vaginal sugar levels that may be caused by increased oestrogen levels. In some women, taking the contraceptive pill can have a similar effect and will also cause thrush. Some women suffer from thrush before their period (premenstrual thrush) as menstrual blood raises the pH level of the vagina, making it less acidic and thereby disturbing the balance between the micro-organisms.
The use of scented bubble bath, soap and vaginal deodorants can irritate the vagina and trigger thrush in some women. Using tampons or wearing nylon tights and underwear can cause thrush to occur and some women find that a diet high in sugar can also cause thrush.
Men usually only develop thrush when it is passed to them by a sexual partner. The symptoms of thrush in men are fairly similar to those seen in women although some men can carry the infection without showing any symptoms at all. They may have itching or burning at the tip of the penis or under the foreskin. A thick, white discharge may also develop under the foreskin and can make it difficult to retract. They may also experience discomfort when passing urine.
Are there any tests necessary?
If it is the first attack of thrush, swabs may be taken to confirm the diagnosis. If the thrush recurs, the symptoms are usually recognised and no further testing should be necessary.
What treatment is available?
Thrush is treated with antifungal creams which are applied locally to the area surrounding the vagina or with antifungal pessaries or cream which are inserted into the vagina. Often a combination of both of these are prescribed at the same time. Examples of topical antifungal agents used to treat thrush include clotrimazole (eg, Canesten®), econazole (eg, Gyno-Pevaryl®), fenticonazole (Gynoxin®) and miconazole (eg, Gyno-Daktarin®). Some treatments for thrush are available to buy from pharmacies without a prescription.
Sometimes antifungals are given orally as tablets or capsules. Oral antifungals used to treat thrush include fluconazole (eg, Diflucan®) and itraconazole (eg, Sporanox®). Single-dose fluconazole capsules (eg, Diflucan® One) are available to buy over the counter from pharmacies.
- Eat yoghurt containing live active cultures - this can increase the levels of naturally occurring bacteria known as lactobacilli, which will help to decrease the levels of Candida albicans and help to prevent recurrent attacks of thrush. Natural yoghurt can also applied directly into the vagina during an attack.
- Cut down on refined sugar (eg, chocolate) - this can also be beneficial.
- Add a tablespoon of vinegar to bath water to relieve symptoms of itching.
- Wear cotton underwear and try to avoid wearing tights or tight clothing.
- Avoid using highly perfumed bubble baths and soaps. Use a simple soap or baby product instead.
- Sexual intercourse during an attack of thrush can be painful. However, if sexual intercourse takes place while one or both partners have thrush a condom must be worn until both partners have been treated to prevent reinfection.
Fact sheet provided by MIMS
Date last reviewed: September 2014