What’s the difference between thrush and bacterial vaginosis?

The who’s who of vaginal infections.

As we clamber our way through adulthood and start having to worry about things like pap smears and sexual health screenings, it can be daunting to realise that many of us have very little clue about what’s happening in our own vaginas.

We know they bleed once a month, and (hopefully) how they like to experience pleasure. But for a lot of people, thinking too hard about their down-there-area can bring up a lot of questions and anxiety. Is it shaped funny? Is that part supposed to feel like that? Does that discharge in my underwear mean I’m dying?

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Because of persisting ideas that it’s shameful or vulgar to discuss our genitals among friends, we tend to neglect vaginal health literacy as a society. As a result, many people can’t identify the difference between healthy vagina quirks and the symptoms of common infections like thrush or bacterial vaginosis (BV).

The first time I heard of thrush as a teenager, an older girl sagely told me it was caused by having sex on the beach. But I’d never even heard of BV until very recently, let alone how the two infections differ.

So, to brush up on vaginal infections 101, I spoke with Dr Deborah Bateson, Medical Director of Family Planning NSW. She ran me through the causes of these two common conditions, how to spot them and how to keep your vagina as happy as possible.

What is thrush?

Thrush is a yeast infection, and it’s caused by an overgrowth of yeast in the vagina. Yeast can live very normally in small amounts in the vagina without causing any problem at all, but in certain situations you can get this overgrowth that will cause the symptoms associated with thrush. The main thing to know is that it’s a very common condition, and that it’s not dangerous.

There are lots of different causes. Wearing sweaty, tight-fitting, synthetic exercise fabrics to do your Pilates or your walks can certainly be associated with thrush. Lots of friction during sex or other activities is another cause. We know women who are pregnant can be more prone to thrush, as well as women who’ve got diabetes because of that excess sugar hanging around, as it were. Taking antibiotics can sometimes cause thrush, as well.

Sometimes it’s hard to know exactly what the cause is. Some women will also have what we call recurrent thrush, where it just keeps coming back again, or even chronic thrush, where it’s really hard to get rid of it. We don’t think that thrush is sexually transmitted, but yeast can occasionally be transferred between partners.

What is bacterial vaginosis?

Bacterial vaginosis is also a very common infection, although people often haven’t heard of it. It’s a discharge that’s caused by an imbalance in what we call the ‘microbiome’. In the vagina, there’s a healthy balance of healthy bacteria, which is why we say the vagina cleans itself. Bacterial vaginosis happens when something disrupts that healthy balance. You get an overgrowth, similar to that overgrowth of yeast, but instead it’s an overgrowth of those bacteria which are usually healthy but cause symptoms when they overgrow.

While we don’t think thrush is sexually transmitted, there’s evidence accumulating that women who are sexually active are more likely to get bacterial vaginosis. We also know that it’s prevalent among women who have sex with women.

Anything that disrupts that healthy bacteria and microbiome can be a cause. Luckily in Australia we’re not big on douching, but douching, cleaning out the vagina with soapy products or putting scented deodorants and all sorts of things into the vagina can certainly disrupt that microbiome.

What symptoms should people be looking out for?

The main thing to know is that it’s normal to have a bit of healthy discharge. It keeps the vagina clean and helps to prevent sexually transmitted infections. I sometimes see women who are very anxious about their discharge, so we examine them and do some tests and it turns out to be completely healthy, physiological discharge.

The thing to look out for with thrush is that it causes inflammation. Women can sometimes present with an inflamed vulva, as well as some vaginal inflammation or little skin splits. The other key thing with thrush is that sort of cottage cheese type of discharge that’s thick and white. Sometimes there can also be burning and pain when you’re urinating or having sex.

With bacterial vaginosis, it’s a little bit different. It’s a milky, thin, whiteish, greyish or sometimes even greenish discharge. Sometimes it’s a bit frothy. Generally thrush doesn’t have an odour associated with it, but bacterial vaginosis can be associated with a bit of a fishy, unpleasant odour. Sometimes there’s itching and pain, but that’s rare.

If someone notices any of these symptoms, what’s the best course of action?

What we really want, rather than people self-diagnosing and maybe self-diagnosing incorrectly, is for people to go see their doctor or a family clinic. If you’ve been diagnosed before, you might know what it is and can institute some treatment, but sometimes there are other, more serious conditions which may be missed. They’re very rare, particularly in young women, but it’s good to just check out what’s going on.

I would suggest, if you’re particularly worried, that you arm yourself with information before you go and see your doctor. You can go on the Family Planning website or a fantastic website called What’s Going On Down There, where you can get information and have a sense of what’s going on. But it’s always a good idea to confirm the diagnosis with your doctor. Because if you think something’s thrush and it’s actually bacterial vaginosis or even an STI, the thrush treatment isn’t going to treat it at all.

How can people prevent these infections?

It’s about basic genital care. You don’t have to actively care for the vagina because it looks after itself, but it’s about looking at what you’re washing your body with, not using highly scented perfumes or bubble baths, and not putting anything on the skin of the vulva that might go into the vagina and disrupt that healthy microbiome.

It’s also your approach to washing your underwear, as well as using cotton underwear and avoiding synthetic underwear. Avoiding underwear at night is helpful if you can do that, wearing loose fitting boxer shorts and things like that instead to get air circulating.

Look at what washing powders you’re using, and if you’re at the gym and you’ve got sweaty, tight-fitting synthetic clothing on, make sure you change and don’t walk around all day afterwards in them. Sometimes using tampons may be preferable to pads, just in terms of irritating the skin, but that’s a personal choice. Those are the main things in terms of genital skin and preventing these infections. But it’s also about health literacy, knowing what’s normal and what’s not normal so you know when to seek help.

In your experience, what level of knowledge does the average person have about vaginal health?

I think it can still be quite low. In school sex-ed, there’s plenty of information on chlamydia and STIs and contraception, but there’s often little education on what’s normal and what’s not when it comes to our bodies. We know, for instance, that people will often mix up the vulva and the vagina, and in turn don’t really know how to look after either.

The other thing is just the stigma and shame some women feel around it all, and that’s because of our society, of course. There’s still difficulty in even saying the word ‘vagina’ sometimes, or ‘vulva’ because people don’t even know what it is. So I think talking about it and making it feel normal to talk about these things is important.

What’s the most important thing you’d like people to know about vaginal health?

Just making sure people know that it’s not an embarrassing thing. Things like thrush or bacterial vaginosis – these are very common infections. We just don’t talk about them with our friends sometimes because it can be a very taboo topic.

We’re much better at talking about menstruation and our periods and things than we used to be, but I think there’s still a bit of a taboo around vaginal discharge in particular. People feel very anxious about it, so it’s important to seek help. There are really good management approaches available, and we’ll have more in the future as we continue our research.

For more on the differences between thrush and BV, head here.