Vaginal Thrush: Symptoms, Causes, and How to Treat It

Vaginal thrush is one of the most common conditions affecting women in New Zealand — and yet many people still feel uncertain about whether what they're experiencing is thrush, what's causing it, and what to do about it.

The good news is that thrush is well understood and usually responds quickly to treatment. This guide explains the symptoms to look for, why thrush develops, and when it's worth speaking to a doctor rather than reaching for an over-the-counter remedy on your own.

What Is Vaginal Thrush?

Vaginal thrush is a yeast infection caused by an overgrowth of a fungus called Candida albicans. Small amounts of Candida are normally present in the vagina without causing any harm. Problems arise when the natural balance of the vaginal environment is disrupted, allowing Candida to multiply beyond its usual levels.

Thrush is not a sexually transmitted infection (STI). It can occur in women who have never been sexually active, and it is not passed on through sex in the same way STIs are — though sexual activity can sometimes be a contributing factor. Partners do not typically need treatment unless they have symptoms themselves.

What Are the Symptoms?

Thrush symptoms can range from mild irritation to quite significant discomfort. The most common include:

• Itching, burning, or soreness in and around the vagina and vulva
  

• Thick, white vaginal discharge with a texture sometimes described as similar to cottage cheese; this discharge usually has little or no odour
  

• Pain or discomfort during sex
  

• Pain or stinging when urinating
  

• Redness and swelling of the vulva
  

• Cracking or soreness of the skin around the vaginal opening in more persistent or severe cases
  

It's worth noting that these symptoms overlap with several other vaginal conditions, including bacterial vaginosis (BV) and some STIs. If you're not certain it's thrush — especially if you haven't had it diagnosed before, if the discharge has an unusual odour, or if over-the-counter treatment hasn't helped — it's important to speak with a doctor before treating again.

What Causes Thrush?

Thrush develops when something disrupts the normal environment of the vagina, reducing the healthy bacteria that keep Candida under control. Common triggers include:

Antibiotics. These are one of the most frequent causes. Antibiotics kill harmful bacteria but also reduce the beneficial lactobacillus bacteria in the vagina, allowing yeast to overgrow. If you've recently been on antibiotics and develop thrush symptoms, this is likely the connection.

Hormonal changes. Fluctuations in oestrogen — during the menstrual cycle, pregnancy, or when starting or stopping hormonal contraception — can alter the vaginal environment and make thrush more likely.

High blood sugar. Women with diabetes, particularly where blood sugar is poorly controlled, have a higher risk of recurring thrush. Yeast thrives on glucose.

Clothing and hygiene habits. Tight or synthetic underwear traps warmth and moisture, creating conditions that favour yeast growth. Perfumed soaps, bath products, or douches can also irritate the vaginal lining and disrupt its natural pH.

Immune changes. Anything that temporarily or chronically weakens the immune system — illness, stress, or certain medications — can make the body less able to keep Candida in check.

When Should You See a Doctor?

Mild, infrequent thrush in someone who has had it confirmed previously can often be managed with over-the-counter antifungal products. However, there are situations where speaking to a GP is the better choice:

• This is the first time you've had these symptoms (a confirmed diagnosis is important before treating)
  

• Symptoms don't improve after completing an over-the-counter treatment course
  

• Symptoms return within a few weeks of treatment
  

• You have thrush four or more times in a year (known as recurrent or chronic thrush — this needs a different management approach)
  

• You're pregnant — treatment options need to be safe for pregnancy
  

• You have diabetes or another condition that may be contributing
  

• You're unsure whether it's thrush or something else
  

Online GP consultations can help in all of these situations. Pocket Lab's registered GPs can assess your symptoms during a discreet video or phone consultation, help confirm whether treatment is appropriate, and issue a prescription if needed — without you needing to visit a clinic. Book a thrush infection consultation or get a women's health lab test.

How Is Thrush Diagnosed?

For most women with straightforward, recurring thrush, diagnosis is clinical — based on the characteristic symptoms and a brief consultation. No swab is always required if the picture is clear.

A vaginal swab may be recommended if:

• The diagnosis is uncertain
  

• Previous treatments haven't been effective
  

• There's a possibility of another infection such as BV or an STI
  

• Symptoms are severe or the thrush keeps returning, in which case a swab can identify whether a less common Candida species is involved (some are resistant to standard treatments)

Treatment Options

Effective treatments for vaginal thrush are available in both over-the-counter and prescription forms.

Topical antifungal treatments — these include vaginal creams or pessaries (tablets inserted into the vagina) containing clotrimazole or miconazole. They are applied directly to the affected area and usually resolve uncomplicated thrush within a few days.

Oral antifungal tablets — a single-dose oral tablet containing fluconazole is a popular and convenient option that many women find easier to use than topical treatments. It requires a prescription, though it can be prescribed online through Pocket Lab. Request a prescription.

Longer treatment courses — for more severe symptoms, or for recurrent thrush, a GP may recommend a longer course of antifungal treatment spanning several weeks, along with a maintenance regime to reduce the frequency of future episodes.

Managing Recurrent Thrush

Some women experience thrush regularly despite treatment. If this is your situation, it's worth a thorough GP review to look for contributing factors — undiagnosed or poorly managed diabetes, antibiotic overuse, or immune issues being among the most common.

In recurrent cases, your GP may recommend:

• Confirming the diagnosis with a swab to ensure it's actually Candida (and identifying which strain)
  

• A longer-term antifungal treatment course, often six months
  

• Reviewing contraceptive choices, as some hormonal methods can be a contributing factor
  

• Dietary and lifestyle adjustments where relevant

Reducing the Risk of Thrush

While thrush can't always be prevented, particularly when antibiotics are necessary, a few practical steps may help reduce how often it occurs:

• Wear breathable, cotton underwear and avoid tight synthetic fabrics
  

• Change out of wet swimwear or gym clothes promptly
  

• Use unscented soap for external washing only — the vagina is self-cleaning and does not need internal washing
  

• Avoid douching or using perfumed products internally
  

• If you have diabetes, keeping blood sugar well managed reduces your risk significantly
  

• When prescribed antibiotics, ask your GP or pharmacist about using a vaginal probiotic or antifungal preventatively if you're prone to thrush after antibiotics

A Note on Partner Treatment

In most cases, a male partner does not need treatment unless he develops symptoms — typically redness, itching, or a rash on the penis. Female partners should be assessed individually if they develop symptoms. Abstaining from sex until symptoms have resolved is generally advisable to avoid discomfort and further irritation.

Getting Help With Thrush in New Zealand

If you have symptoms consistent with thrush and want a professional assessment, Pocket Lab GPs are available seven days a week from anywhere in New Zealand. A consultation takes around 15 minutes, and any prescription is sent directly to a pharmacy of your choice — or can be arranged for delivery in some cases.

This article is for informational purposes only and does not replace individualised medical advice. If you're unsure about your symptoms, please consult a registered New Zealand GP before beginning treatment.