Some women find taking preventative measures doesn’t seem to help much, but others find they do make a difference. So it makes sense to try the following:

• Change underwear daily and wash underwear in hot water (this destroys fungi).
• Candida likes moist, warm places. So avoid wearing tight-fitting clothing like jeans and pantyhose, and underwear made from synthetic fibres and panty liners.
• Avoid douching, or taking baths with bubble-bath, soap and bath salts, as these can upset the natural balance of the vagina.
• Don't clean the skin around your vagina more than once a day. You can use water and a moisturiser as an alternative to soap.
• Apply moisturiser to the skin around your vagina several times a day. Note that this can weaken condoms.
• Keep your immune system strong and healthy by eating a well-balanced diet, getting plenty of exercise, and not smoking.
• If you are prescribed antibiotics for any reason, ask your doctor whether you should take anti-fungal medications as a precautionary measure.
• If you have diabetes, keep your blood sugar levels under control.
• Always wipe from front to back after going to the toilet.

There isn’t any good evidence that changing your diet will help prevent thrush, although some women find that eating yoghurt or other products containing lactobacilli (so-called ‘good’ bacteria), will help. But applying plain yoghurt directly to the vagina won’t be much help in treating or preventing thrush.