Vaginal thrush is a common condition caused by a yeast infection in the vagina and surrounding area.
The infection is usually Candida albicans, but is also known as candida or vulvovaginal candidiasis.
Candida lives harmlessly on the skin, in the mouth, gut and vagina and is normally kept under control by harmless bacteria.
But sometimes conditions change and the yeast increases rapidly, causing symptoms of discharge and irritation.
What causes vaginal thrush?
Thrush is not considered to be a sexually transmitted infection, although occasionally it is passed on during sex. More often it is an overgrowth of the Candida yeast which is already there but not previously causing a problem.
The immune system and the harmless germs (bacteria) that also normally live on the skin and in the vagina usually stop Candida spp. from thriving. However, when conditions are good for Candida spp., numbers multiply and may invade the vagina and cause symptoms. This could be due to changes in the bacteria in the vagina when you have taken antibiotics. Or it could be related to hormone changes, or problems with your immune system.
Most causes of thrush are a result of Candida albicans but sometimes other types of Candida spp. such as Candida glabrata or Candida tropicalis are the cause.
Who gets thrush?
Most women get thrush at some point in their life, but it is most common in women in their thirties and forties, and in those who are pregnant.
It is not clear why some women are more prone to thrush than others. Diabetes and medical conditions that cause problems with the body’s immune system increase the likelihood of it occurring.
Other potential triggers include:
- wearing tight clothing – this prevents natural ventilation
- taking antibiotics – about 30 per cent of women will have thrush because of this
using products that irritate the vagina, such as vaginal douches or bubble bath
- having chemotherapy.
There is little evidence that using sanitary towels or tampons is a risk factor for developing thrush.
What are the symptoms of thrush?
Some women with thrush will not have any signs or symptoms, and be completely unaware they have thrush. It may only be picked up by chance when you go for a cervical smear test.
In women, typical symptoms include:
- vulval itching, soreness and irritation
- redness of the vagina and vulva
- vaginal discharge, often white (like cottage cheese) and this can be thick or thin but is usually odourless
- pain or discomfort during sex or when passing urine.
In men, symptoms may be less noticeable than in women, but include:
- discomfort, burning or itching at the tip of the penis or under the foreskin
- redness or red patches on the penis or under the foreskin
- a thick or thin discharge, like cottage cheese, under the foreskin
- discomfort when passing urine.
How is vaginal thrush diagnosed?
You do not always need a test to diagnose thrush. The diagnosis is often based on the typical symptoms and signs.
It is important that you do not assume that a vaginal discharge is thrush. There are other causes of vaginal discharge. It is reasonable to assume it is thrush if:
- You have a vaginal and/or vulval itch.
- Any discharge you have does not smell and is white or creamy.
- You have no abnormal bleeding.
However, if you have assumed you have thrush and you have had treatment, but the symptoms have not gone away, you may need to have tests. See your doctor, who may examine you and may perform some tests.
If tests are needed they may include:
- A test to see how acidic the vagina is (a pH test). The level of acidity gives an indication of whether a discharge is due to thrush or to bacterial vaginosis. This is the basis of the over-the-counter test for thrush. A test strip is placed into the vagina and then the colour change indicates if thrush is likely or not. A pH level of 4.5 or less suggests thrush. Some doctors may also use this test.
- A swab. This is a stick with a cotton bud at the end of it. A sample of discharge is taken from the vagina and analysed in a lab. This indicates if you have thrush or another infection. It can also inform the doctor which type of candida you have.
- Tests for other infections. Further swabs may be taken to be sure you do not have other types of vaginal infections.
- Urine tests. Your urine may be checked for sugar. This is to check you do not have diabetes, as this would make you more prone to thrush. This might be done if you were getting repeated (recurring) episodes of thrush. Urine may also be checked for infection, as sometimes it can be difficult to distinguish between a urine infection and thrush.
Treatment of vaginal thrush
Treatment of thrush involves the use of antifungal creams, vaginal pessaries and/or oral medication. Many of these treatments are now available over the counter (no prescription required). Women who choose to self-treat with over the counter thrush preparations should see their doctor if symptoms persist or recur as they may have a different condition (e.g. bacterial vaginosis, dermatitis, lichen sclerosis, genital herpes) or a resistant strain of thrush. Recurrent thrush infections (those that have been confirmed by a doctor) may require a longer course of treatment before they go away.
In view of the fact that only 34% of self diagnosis and self medication of thrush in women is correct and the rest are incorrect diagnoses, women should consult their doctor before they try to instigate treatment.
If symptoms are mild, your doctor will usually recommend a short course of antifungal medicine, usually for one to three days.
If the symptoms are more severe, the treatment course will be longer.
A variety of treatment options are available including taking tablets orally, inserting them into your vagina (pessaries) or using a cream. Tablets and pessaries work equally well.
Your GP can prescribe these treatments and you can also buy them over the counter.
Tablet antifungal treatment is typically fluconazole (eg Canesten oral, Diflucan).
They can be extremely effective, and one tablet taken once may be enough to cure an episode of thrush.
Occasionally they cause side-effects such as nausea and vomiting, diarrhoea or constipation and bloating.
Pregnant or breastfeeding women are not usually prescribed tablet antifungal treatments because of the theoretical chance they may affect the baby.
Intravaginal pessaries do not cause as many side-effects as tablet treatments, but they can be awkward and messy to use, can cause local irritation, and can damage latex condoms and diaphragms.
The medicines clotrimazole (eg Canesten), econazole (eg Ecostatin) and miconazole (Gyno-Daktarin) come in pessary form.
If you are pregnant, don’t use the applicator to insert the pessary because there is a risk of causing injury to the cervix. Instead, insert the pessary by hand.
Creams can be used in addition to pessary or tablet treatment if there is localised redness and soreness around the vagina and vulva.
Do I need to see a doctor if I get vaginal thrush?
If you have had thrush in the past and the same symptoms come back then it is common practice to treat it without an examination or tests. Many women know when they have thrush and treat it themselves. You can buy effective treatments without a prescription from pharmacies.
However, remember a vaginal discharge or vulval itch can be due to a number of causes. So, do not assume all discharges or itches are thrush. The following gives a guide as to when it may be best to see a doctor or nurse if you think that you might have thrush. If you:
- Are under 16 or over 60 years of age.
- Are pregnant.
- Have treated yourself with a thrush treatment from the chemist, but your symptoms have not gone away.
- Have abnormal vaginal bleeding.
- Have lower tummy (abdominal) pain.
- Are unwell in yourself in addition to the vaginal and vulval symptoms.
- Have symptoms that are not entirely the same as a previous bout of thrush. For example, if the discharge has a bad smell, or it you develop ulcers or blisters next to your vagina.
- Have had two episodes of thrush in six months and have not consulted a doctor or nurse about this for more than a year.
- Have had a previous sexually transmitted infection (or your partner has).
- Have had a previous bad reaction to anti-thrush medication or treatments.
- Have a weakened immune system – for example, if you are on chemotherapy treatment for cancer or are taking long-term steroid medication for whatever reason.
- And if you do treat yourself, see a doctor or nurse if the symptoms do not clear after treatment.
What can I do to prevent thrush?
As well as using antifungal medicines, there are a number of things you can do to help ease thrush.
- Wash your vaginal area with non-perfumed soap and water, or water alone. Avoid using highly-scented soaps, shower gels, vaginal deodorants or douches.
- Avoid using latex condoms, spermicidal creams and lubricants if they cause irritation. Instead, try using non-allergenic condoms.
- Avoid wearing tight-fitting clothes made of artificial fibres such as nylon.
- Whenever possible, wear cotton underwear and loose-fitting clothes rather than tight ones.
Some women who suffer regularly from vaginal thrush use live yoghurt – either as a cream or on a tampon – to help treat it.
Although there is no firm medical evidence that this type of treatment is effective, there is no reason to believe it is unsafe and many women report significant relief of symptoms.