Candidiasis (thrush)

Candidiasis, or thrush, is a condition caused by an overgrowth or hypersensitivity to a fungus or ‘yeast’ called candida.

This yeast is normally found on the skin and in the vagina.

It most commonly affects the vagina but can also affect the glans (head) of the penis.

It is not a sexually transmitted infection.


Symptoms can occur at anytime but are most common with:

  • the use of antibiotics
  • pregnancy
  • high dose contraceptive pills before a period
  • medications or illnesses that suppress the immune system
  • diabetes mellitus.


The main symptom in women is itchiness around the vulva or inside the vagina. They may also have a discharge from the vagina that is usually thick and white.


Men may notice itchy red spots on the head of the penis and under the foreskin.

Other problems it can cause

Thrush does not cause other problems.

However, if it keeps coming back after treatment it may indicate you have lowered immunity or diabetes.


Usually the doctor or nurse will be able to diagnose thrush from its symptoms.

A swab from the vagina or penis can be taken to look for the yeast; however treatment is only needed if there are symptoms.


Candidiasis is easily treated with a short course of anti-fungal creams or pessaries (small tablets that dissolve when placed in the vagina).  Treatment is available from a chemist without a doctor’s prescription. You will be more comfortable if you avoid tight clothes while you have symptoms.

Alternative treatments such as vinegar, yoghurt or lactobacilli may give some short-term relief but will probably not cure the condition.

If women have repeated episodes of thrush, longer-term treatment or oral tablets can be used.

Candidiasis is not a sexually transmitted infection but if someone does have vaginal discharge they should have a checkup in case they have an STI, especially if they are under 35 or have a new sexual partner.


For more information contact Centre for Disease Control's Clinic 34.

Last updated: 12 May 2016

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