Vaginal yeast infection, also known as thrush or candidiasis, is one of the most common vaginal infections. During their lifetime, a whopping 75% of women will experience at least one episode of vaginal yeast infection¹. And many women will experience yeast infections recurrently.  

While its technical name is ‘vulvovaginal candidosis’ or VVC, we will be referring to it also as yeast infections or thrush interchangeably throughout this article for ease of understanding and communication.

Contrary to the stigma out there, for people with vaginas to experience a yeast infection is entirely normal. It can be unpleasant, but it does not mean that you’re unhygienic or have done anything wrong.

Don’t be afraid to talk about it with your partner, close family or friends, your local pharmacist and GP. The more that we normalise the discussions around vaginal health, the more easily accessible treatment and prevention will become.

In this story we cover:

• What are the symptoms of yeast infections?
• What are the causes of yeast infections?
• What are the treatment methods for yeast infections?
• How can you prevent yeast infections?

1.  Vaginal yeast infection symptoms 

Unfortunately the symptoms of vaginal thrush are uncomfortable - they include:

• Thick, white (cottage cheese-like consistency) discharge, that tends to be odourless
• Itching
• Soreness
• Burning sensation
• Redness and swelling of vulva
• Thinning of the vaginal wall
• Pain during or after intercourse – this is also known as dyspareunia
• Burning sensation during urination due to salt from urine irritating vulvar skin (vulvar dysuria)

2.  What are the causes of vaginal yeast infections? 

Yeast infections are caused by overgrowth of the fungus Candida. The vaginal microbiome may have small amounts of yeast at any given time without causing any symptoms. This is because the good bacteria – Lactobacilli – keep the fungus under control.

However, when conditions change in the vaginal microbiome, and too much yeast grows, you can get an infection.

Factors that can contribute toward vaginal yeast infection are:

• Cycle changes – some people experience vaginal yeast infection symptoms just before their period²
• Use of antibiotics – some people get thrush following a course of antibiotics
• Immunosuppression – some people get thrush due to being run down or have a weaker immune system
• Diabetes can make you more prone to getting thrush or a yeast infection
• Hormonal changes – In puberty, with rising in estrogen levels, vaginal epithelial cells multiply. Estrogen levels oscillate during the menstrual cycle with its peak in the middle of the cycle. Increased estrogen leads to increase in intracellular glycogen in the vaginal mucosa. Glycogen is used as a food by lactobacilli population present in vagina. Breakdown of glycogen results in an increase in lactic acid, and subsequently lower pH (3.8-4.5). Low pH inhibits the growth of certain bacterial species³, but unfortunately, Candida can thrive in low pH. High estrogen levels, due to the use of contraceptive pills, hormone replacement therapy and pregnancy, can cause the overgrowth of Candida species in a vagina⁴.
• Use of vaginal washes, soaps, deodorants and lubricants that are irritating and disturbing for vaginal microbiome
• Sexual behaviour – Sexual interactions were not considered relevant for yeast infections for a long time. However, it has been shown recently that sexual activity has a role in the transmission of yeast infections⁵. It was found that transmission of yeast infections was particularly prevalent where sex toys or aids, oral sex, male masturbation with saliva followed by vaginal sex and receptive anal sex⁶ were involved.  

If you find yourself in a situation where you’ve contracted a vaginal yeast infection it’s important to remember that it’s totally normal, and as you can see from the varied list of causes and risk factors that it can be unavoidable.

3.  What is a treatment for vaginal yeast infections? 

If you are experiencing the symptoms above, consult with your healthcare provider who would be able to accurately diagnose your vaginal infection. It is important to seek medical advice before self-medicating so you can be sure of the type of vaginal infection you have and can treat it accordingly.

Your healthcare professional can prescribe the right treatment based on your stage of life and health status. Pregnancy, menopause, hormonal therapies, immunosuppressive therapy and diabetes are all factors that your healthcare provider may take into consideration when prescribing treatment.

The treatment may include use of products that will be applied orally or vaginally. Common treatments include:

• Pharmaceutical treatment - oral or vaginal azoles^7:
• Vaginally Clotrimazole cream 1 or 2% (for 7 or 3 days respectively)
• Vaginally Miconazole cream 2 or 4% (for 7 or 3 days respectively)
• Vaginally Teroconazole cream 0.4 or 0.8% (for 7 or 3 daysrespectively)
• Oral Fluconasole 150 mg (single dose or 2 sequential doses for complicated VVC, where second dose is applied 72 hours after initial dose)
• Vaginally Boric acid 600mg hardshell capsule (once daily for 3 weeks) - recommended in VVC recurrence. (Boric acid is included as part of multiple national health guidelines globally (including the United Kingdom and the United States) for the treatment of vaginal yeast infections.)
• Vaginal microbiome support:
• Vaginal probiotics – recommended in VVC recurrence to support vaginal microbiome⁸  

4.  How can you prevent vaginal yeast infections?

Even with current treatments available, you may be experiencing recurrent vaginal yeast infections. A 2018 study estimated 138 million women suffer from recurrent vaginal thrush infections, so if you seem to keep getting yeast infections, rest assured that you are not alone.

While it can be frustrating and embarrassing, there are some things that you can do. These fall under three categories: 1) restoring a healthy microbiome, 2) changing your diet and lifestyle, and 3) consistent anti-fungal treatment if you are prone to recurrence.

Probiotics

• Vaginal microbiome health may be supported with Lactobacullus bacteria^8,9. A randomized, double blind and placebo controlled clinical study was conducted with women suffering from VVC¹⁰. The participants were divided into 2 groups: one group received Fluconasole 150mg orally with probiotic strains L. rhamnosus, GR-1^® and L. reuteri, RC-14^® daily over 28 days. The other group received Fluconasole together with a placebo capsule. The patients in the probiotic group experienced reduction in symptoms, significantly less discharge (only in 10% compared with 35% of the patients in the placebo group), and reduced Candida detection (only in 10% compared with 39% of the patients in the placebo group). At the follow up after 4 weeks, the probiotic group still had less Candida detection (18%) than the placebo group where Candida could be detected in 80% of the patients.
• Probiotics for vaginal health come in both oral and vaginal forms. Oral capsules are usually taken daily for at least 30 days, while vaginal pessaries are usually taken intra-vaginally daily for a shorter period of time (5-10 days). 
• Your healthcare professional may recommend taking probiotics monthly on an ongoing basis in order to support the vaginal microbiome environment over a period of time.

Foods and lifestyle

• Yogurt - Some people use vaginal application of yogurt at first onset of symptoms, often coating a tampon with yogurt, and find it helpful. However, we could not find anything other than anecdotes to support this so would not recommend this practice as a prevention method. In fact, there are a few reasons to avoid yogurt. 
• Diet - There are also studies to support modification of diet and lifestyle: reduce the intake of simple sugars and fat, and increase intake of foods rich in folate, vitamins A, C, D, E, calcium and beta-carotene¹¹. Some of these diets can be very restrictive and may have other implications nutritionally so we would recommend consulting with your healthcare professional before attempting these diets.
• Address hygiene factors by wearing clean, breathable underwear and only using good quality vaginal products that are pH and osmotic pressure balanced, with no irritants, such as artificial fragrances and flavours. 

Anti-fungal treatment

• Your healthcare professional may recommend a longer course of anti-fungal treatment either vaginally or orally.  Ensure that you speak to your healthcare professional before medication use because, in some cases, repeated use of antifungal treatments can lose their efficacy overtime.
  
  Like with many vaginal and urinary tract infections, unfortunately, it seems some people are simply prone to recurrent yeast infections. If this is you, please remember: you can be doing all the right things and still experience symptoms. 
  
  You don’t need to feel alone. There are multiple Facebook groups based all over the world where people who suffer from recurrent vaginal infections are sharing and experiencing something similar.