What is thrush?

Also known as vulvovaginal candidiasis, or candida, thrush is a common fungal infection that can make your vagina and vulva (the outer lips) feel sore and itchy.

About 75% of women will have thrush at least once, and most get it in their 30s and 40s.

Thrush develops when there’s an overgrowth of naturally occurring yeasts called candida. There are over 20 candida species that can cause an infection, but candida albicans is the most common.

What causes thrush?

A small amount of candida yeasts live on moist areas of healthy skin and they’re part of the normal flora (healthy bacteria) of your vulva and vagina.

If candida yeasts multiply, it can lead to an infection and symptoms can develop. This can happen when there’s an imbalance of bacteria, and the conditions are right for candida to grow, due to any of the following:

  • Antibiotics: Taking a course of antibiotics can kill off the good bacteria in your vagina, meaning yeasts are more likely to overgrow
  • Changes in hormone levels: You’re more likely to get thrush before your period, if you’re on the pill, or when you’re pregnant, because of hormone changes in the vagina that promote yeast growth. Similarly, if you have diabetes, high blood sugar levels can feed the yeast
  • A weakened immune system: If you’re feeling run down, taking steroids, on chemotherapy, or you have uncontrolled diabetes or HIV, your immune system will be weaker, so it’s harder to fight off infections like thrush
  • Sex: Semen has a different pH to your vagina, so contact during sex can sometimes disrupt the balance of bacteria in your vagina, triggering thrush
  • Lubricant or spermicide: Some lubricants are sugar-based, which can prompt yeast growth. Also, using spermicide, or condoms that contain spermicide, kills good bacteria as well as sperm
  • Hygiene: Over-cleaning with highly perfumed soaps can cause irritation and disrupt the natural pH balance of your vagina, making yeast more likely to grow
  • Clothes: Yeast thrives in warm, moist, airless places, so if you wear synthetic underwear or tight-fitting trousers, you can be more prone to thrush.

What are the symptoms of thrush?

Symptoms can differ between women and between episodes. They can also range from mild to more severe. Don’t worry, thrush won’t cause permanent damage to your vulva or vagina, and if you’re pregnant, it won’t harm your baby.

Milder symptoms include:

  • An itchy vulva/vagina
  • A sore vulva/vagina
  • Slightly swollen labia
  • Odourless, curdy discharge (discharge can also be thin or absent).

More severe symptoms include:

  • Red, swollen labia
  • Pain when you urinate
  • Pain during sex
  • Burning around your vulva/vagina
  • Sores or cracked skin on your vulva.

You should see a doctor if any of these apply to you:

  • Your symptoms don’t improve within 3 days, or they’ve not gone away within 7 days
  • This is the first time you’ve had thrush
  • You have thrush that keeps coming back (recurrent thrush)
  • You’ve used an over-the-counter treatment, but your symptoms haven’t gone away
  • You have diabetes
  • You have a weakened immune system
  • You’re under 12
  • You’re pregnant or breastfeeding
  • You have multiple sexual partners
  • You have a smelly or unusual discharge
  • You have a fever, chills or nausea
  • You have lower tummy pain
  • You have abnormal vaginal bleeding
  • You’ve had an allergic reaction to thrush medications before.

How is thrush diagnosed?

If you have an itchy or sore vulva and vagina, with an odourless, curdy discharge, you can self-diagnose thrush. If you’re not sure, speak to your pharmacist and they’ll be able to help.

You can also get an over-the-counter pH test to confirm you have thrush and not bacterial vaginosis. This involves placing a test strip in your vagina, and if the colour change shows that it’s acidic (a pH of 4.5 or less) it’s likely to be thrush.

If you see your doctor, they may offer:

  • A clinical examination – to help them make a diagnosis
  • Swab test – a sample of the discharge is taken from your vagina to analyse in a lab and determine whether it’s thrush, as well as what kind of yeast is causing the infection
  • Further blood tests or urine tests – if you have recurrent thrush
  • Prescription anti-fungal treatment – if they diagnose you with thrush.

How is thrush treated?

Mild symptoms of thrush can clear up on their own. If your symptoms persist, you don’t always need to have an examination or test – you can buy over-the-counter anti-fungal medicines without a prescription:

  • Pessaries – these are inserted into the vagina with an applicator to work directly on the infection, e.g. clotrimazole
  • Creams – these can be applied to the vulva to relieve the external itching and soreness
  • Oral tablets or capsules – a single dose of fluconazole.

You can use a pessary, cream and oral treatment together or separately. Check with your pharmacist if you’re taking any other medication to make sure it doesn’t interact. If you’re pregnant or breastfeeding, you can use creams but not the oral thrush treatment.

You don’t need to avoid sex from an infection point of view because thrush isn’t a sexually transmitted infection. But if you’re sore, you may want to wait until your symptoms have improved before you have sex.

Also, it’s important to know that pessaries and creams can damage condoms and diaphragms, so make sure you read the information that comes with the medicine.

Why you might still have symptoms

If it’s been a week since you started treatment and you still have symptoms, you should see a doctor. It may be that:

  • your treatment has only been partially effective
  • you may have had an allergic reaction to the pessary or cream
  • you haven’t used the treatment correctly
  • you’ve had another bout of thrush in close succession
  • you have something other than thrush, such as bacterial vaginosis or a skin condition (see related conditions below)
  • your thrush is caused by a different type of yeast such as candida glabrata or candida tropicalis, so you’ll need a prescribed anti-fungal treatment.

Treatment for recurrent thrush

Recurrent thrush is defined as four episodes or more in a year with two episodes confirmed by lab tests. We don’t know why recurrent thrush happens, but some women are simply more prone to developing thrush.

It’s important that you see a doctor for a check-up if you’re getting recurrent episodes of thrush. Your doctor may offer:

  • a clinical examination – to check that the symptoms are due to thrush
  • a swab test – to confirm it’s thrush and so they know which anti-fungal treatment to use
  • blood tests and/or urine tests – to check your immunity, iron levels and whether you have diabetes
  • maintenance treatment – this involves a longer course of initial treatment followed by treatment once a week for six months.

Usually you’ll be free of thrush while you’re on maintenance treatment, and stay this way after treatment. See your doctor if you get thrush while on maintenance treatment, as you may have a different type of candida yeast, which needs an alternative treatment.

Self-care for thrush

There are a few things you can do to relieve your symptoms, as well as prevent further bouts of thrush:

  • Avoid perfumed soaps or wipes
  • Wash your vulva with water and unscented soap
  • Avoid vaginal douching
  • Use an emollient on your vulva to moisturise and protect the skin
  • Wear loose-fitting, cotton underwear and trousers
  • When washing your underwear, use non-bio detergent and avoid fabric conditioners
  • Avoid using daily pads
  • On your period, use unscented pads instead of tampons, and change them frequently.

Related conditions

It’s important to know that you can get similar symptoms from the following conditions:

  • Bacterial vaginosis (BV): Sometimes mistaken for thrush, bacterial vaginosis is an overgrowth of certain types of bacteria (not sexually transmitted) and is treated with antibiotics. If your discharge is smelly, and your vulva isn’t itchy, it’s more likely to be BV
  • Sexually transmitted infections (STIs): For example chlamydia and gonorrhoea have symptoms such as unusual vaginal discharge and a burning sensation while urinating, so if you have these symptoms without the itching, it’s best to get an STI test
  • Skin conditions: For example lichen simplex can cause soreness and itching and is treated with topical steroid cream.

Reviewed by: Mrs Caroline Overton