Thrush

What is vaginal thrush?

Vaginal thrush (candida or candidiasis) is a common fungal infection of the vagina caused by an overgrowth of a yeast (a type of fungus) called Candida. Also known as a yeast infection, thrush affects around 75% of women at least once during their lifetime.

Thrush is not a sexually transmissible infection (STI). However, sexual activity can make symptoms worse and male sexuale partners may get some redness or irritation of the penis.

What are the symptoms of thrush?

Typical symptoms of thrush include:

• itching or burning of the vagina and/or vulva
• white vaginal discharge
• pain during sex
• stinging when urinating (weeing)
• swelling or redness of the vulva and vagina
• splits in the skin of the vulva.

What causes vaginal thrush?

The vagina is home to many different micro-organisms such as bacteria and fungi, including a type of bacteria called Lactobacillus. These bacteria usually keep the amount of Candida in the vagina under control. However, if levels of lactobacilli are disrupted, an overgrowth of Candida can occur, leading to the symptoms of vaginal thrush.

It’s also thought that higher oestrogen levels can make women more prone to thrush. Oestrogen increases the amount of glycogen (a type of sugar) in the vagina, which provides an ideal environment for Candida to grow and thrive.

Who is at risk of developing thrush?

Because oestrogen levels impact Candida growth, thrush usually occurs in women who have periods, as they have higher levels of oestrogen. Thrush is rare in girls who have not yet gone through puberty, and in postmenopausal women unless they are on oestrogen therapy. Women who are at higher risk of developing thrush include those who:

• have recently taken antibiotics
• use a higher dose combined oral contraceptive pill
• use oestrogen-based menopause hormone therapy (MHT), including vaginal oestrogen cream
• are pregnant
• experience changes in the menstrual cycle usually in the premenstrual time
• have other health conditions such as obesity, diabetes, iron deficiency and immune system disorders
• have vulval skin conditions such as vulval psoriasis, lichen planus or lichen sclerosus.

How is thrush diagnosed?

Your doctor will ask questions about your symptoms, past health history and family health history. A physical examination will include an examination to check your vulva and vagina. Your doctor will also take a swab from your vagina and send it to a laboratory for testing to check for the presence of Candida.

Often women who have had thrush before will go to the pharmacy to get over-the-counter treatment (medicine that you can buy without a prescription). If the treatment does not work and symptoms come back, it is important to see your doctor for an examination and vaginal swab to check if there may be another cause.

Treatment for thrush

Treatment for thrush aims to reduce the amount of yeast in your vagina and reduce symptoms. Candida albicans is responsible for 95% of thrush infections , but some other species (types) of Candida can also cause the infection.

Treatment for thrush caused by Candida albicans is sometimes referred to as azole therapy and usually involves:

• Antifungal creams or vaginal pessaries containing clotrimazole, miconazole or nystatin – these are inserted into the vagina using a special applicator. Treatment time can range from one to six days, depending upon the product and severity of symptoms. For 90% of women with mild symptoms, one to three days of treatment will be enough. Sometimes it may be necessary to have a second course of treatment.
• Oral antifungal medicines (tablets or capsules you swallow) containing fluconazole or itraconazole – these are usually used for severe or recurrent thrush infections. However, these medications may interact with other medicines, particularly statins which are used for high cholesterol.

If thrush is caused by a type of Candida that is not Candida albicans, treatment will usually be different because azole therapy is often not effective against other species.

When you have thrush, sex can be painful or cause a burning feeling. So if this happens you might want to avoid sex until after you have finished treatment.

It is also inportant to know that thrush creams can weaken condoms, so apply creams after sex.

Recurrent thrush

Recurrent thrush is when you have four or more episodes of thrush over 12 months. Around 5% of women experience recurrent thrush. Recurrent thrush is usually due to persistent infection (ie the initial thrush treatment was not effective) rather than a new infection. However, in some women, recurrent thrush may be a sign of other health conditions such as:

• iron deficiency
• diabetes
• immune disorders.

If you think you have recurrent thrush, it is important to see your doctor rather than self-diagnose your condition, as symptoms of thrush can be similar to other vulval or vaginal conditions. If your doctor thinks you have recurrent thrush, they may investigate if other underlying conditions are the cause. Treatment may also involve:

• combined vaginal and oral azole therapy
• oral antifungal medication (usually fluconazole) taken regularly for up to six months
• a change in contraception
• changing to a lower oestrogen dose of MHT.

Complications of thrush

Untreated or recurring thrush can lead to ongoing vulval pain or pain during sex, so it is important to seek treatment. There is also the risk of cracks or splits (fissures) in the vulva, which may become infected.

When to see your doctor

If you experience unusual symptoms relating to your vagina or vulva, it is important to see your doctor. This is because other vulval or vaginal conditions can have symptoms similar to thrush. You should see your doctor if:

• you experience thrush-like symptoms for the first time
• you are unsure whether your symptoms are related to thrush
• your thrush has not improve despite treatment
• you continue to have painful sex after the thrush treatment is finished
• you self-diagnosed and treated your thrush, and your symptoms haven’t gone away
• you experience recurring episodes of thrush
• you have thrush-like symptoms while you are pregnant or breastfeeding
• you have pain in your pelvic or vulval area
• you experience abnormal vaginal bleeding.

What you can do

These recommendations and lifestyle changes can also reduce your risk of thrush. You can:

• wipe from front to back after going to the toilet. This will prevent the spread of Candida albicans from the anus into the vagina
• avoid using soap, shampoos, detergents or talcum powder on your vulva
• avoid perfumed or scented toilet papers, pads or tampons
• avoid tight-fitting pants, pantyhose and synthetic underwear
• wash clothing in non-perfumed, low-allergenic products and avoid fabric softeners
• wear cotton underwear
• do not douche (internal vaginal wash).

This web page is designed to be informative and educational. It is not intended to provide specific medical advice or replace advice from your health practitioner. The information above is based on current medical knowledge, evidence and practice as at October 2021.