Vaginal thrush - 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.

Over 90% of cases of thrush 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 believed that a change in the natural balance of the vagina leads to the growth of Candida and causes the symptoms of thrush.

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

What increases your chances of thrush?

Your risk of developing thrush increases if you:

  • take antibiotics
  • are pregnant
  • have poorly controlled 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 – when your blood glucose levels go up and down, rather than being 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: 07/05/2014

Next review due: 07/05/2016


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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

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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.

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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

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nooneone said on 28 September 2010

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

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Myths and facts

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


It is possible that some contraceptives, particularly the combined pill, can increase your risk of getting thrush. Other types of progesterone contraception that stop ovulation may reduce your risk of getting thrush.

However, there's hardly any evidence to support this.

Tight-fitting clothing

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

Female hygiene

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

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