Thrush, vaginal - Causes 

Causes of vaginal thrush 

Vaginal thrush is a yeast infection that is usually caused by a type of fungus that lives naturally in the vagina.

Most cases of thrush (80-90%) are caused by Candida albicans. The rest are due to other types of Candida fungi.

Up to half of women have Candida living naturally in their vagina without it causing any symptoms.

It's thought that there has to be a change in the natural balance of the vagina that leads to an explosion in the growth of Candida and causes the symptoms of thrush.

This change can be a chemical change, such as when you take antibiotics, or it can be a hormonal change, for instance, during pregnancy.

What increases your chances of thrush?

Your risk of developing thrush increases if you:

  • take antibiotics
  • are pregnant
  • have diabetes
  • have a weakened immune system


Thrush happens in about a third of women who take antibiotics because antibiotics get rid of the friendly bacteria in the vagina.

Any type of antibiotic can increase your chances of developing thrush. But for you to develop the yeast infection, the Candida fungus must already be present in your vagina.


If you're pregnant, changes in the levels of female hormones, such as oestrogen, increase your chances of developing thrush and make it more likely to keep coming back.


Diabetes is a long-term condition that's caused by too much glucose in the blood. It's usually kept under control by having regular insulin injections and maintaining a healthy, balanced diet.

If you have poorly controlled diabetes – that is, your blood glucose levels go up and down rather than staying stable, you are more likely to develop thrush.

Weakened immune system

Your risk of developing thrush is also increased if your immune system is weakened – for example, when you have an immunosuppressive condition, such as HIV or AIDS, or if you are having chemotherapy.

This is because in these circumstances your immune system, which usually fights off infection, is unable to control the spread of the Candida fungus.

Read about how thrush is diagnosed.

Page last reviewed: 17/02/2012

Next review due: 17/02/2014


How helpful is this page?

Average rating

Based on 193 ratings

All ratings

Add your rating


The 4 comments posted are personal views. Any information they give has not been checked and may not be accurate.

User850959 said on 03 March 2014

please please can someone out their help me. im not sure if i have thrush anymore i think i could be coming back as my vaginal area is smelling, Im having pain there, white stuff is coming out. i honestly dont know what to do anymore i have been putting E cream there when it starts to hurt but it is hardly working. Please can some one help me tell me whats going on what i can use or anything

Report this content as offensive or unsuitable

Snoozy Q said on 10 December 2013

Washing your hair in the bath is a recipe for thrush. Soaps are well known for causing an outbreak of thrush. You should not use soap on your Nether region or sit in a bathtub full of it.

Report this content as offensive or unsuitable

bigger said on 19 January 2013

please please please can someone help me im so fed up with getting thrush, I have suffered for a long time with it over the last year I had it about 10-15 times and now its worse.
I had it on the 3-4 dec then again on the 4th jan and now again, I go to the doc and even my gu clinic who very kindly done a blood test which shows my iron levels are low ,iv been taking iron tablets for 3 weeks and still got it again, its driving me crazy....I have I b s and am very careful, I don't wear underwear and haven't done for years because of this, I don't use soap and shower off with plain water if I wash my hair in the bath I don't use my clothes with fabric softer
its getting me down and is effecting my sex life to
I had intolerances testing done for my ibs which showed milk,caffine,malt,barley,coco .
please help me I don't know what else to do

Report this content as offensive or unsuitable

nooneone said on 28 September 2010

do you mean women giving oral sex are more at risk? or women receiving it....? please be clear

Report this content as offensive or unsuitable

Myths and facts

The following have, rightly or wrongly, been suggested as potential causes of thrush:


It's thought that some contraceptives, particularly the combined pill, can increase your risk of getting thrush.

However, there's little hard evidence to support this.

Tight-fitting clothing

Wearing tight-fitting clothing may increase your risk of developing thrush. However, the evidence to support this is uncertain.

Female hygiene

There's also little evidence to suggest that sanitary towels, tampons or vaginal douching increase your chances of getting thrush.

Symptom checker

If you have a health problem, our symptom checker can help you manage it or find out where to go for help

Women's health 18-39

Healthy living advice for women aged 18-39 including real stories, fitness, diet, fertility and sexual health

Two friends

Living with diabetes

How to live healthily with diabetes, including advice on diet and lifestyle