What is Bacterial Vaginosis (BV)?

Bacterial vaginosis (BV) is a common infection that occurs in the vagina. This is caused when the balance of bacteria in your vagina changes. It can affect women at any age. The main symptom is watery, grey/white vaginal discharge with a strong, fishy smell, but you may get no symptoms at all.

What causes BV?

BV is caused when the natural balance of bacteria in your vagina changes. What causes this to happen is currently not known, but you may be more likely to get it if you:

• are sexually active
• have an IUD (intrauterine device), which is a type of contraception inserted into your womb
• have a change in sexual partner
• have used perfumed products around or in your vagina

BV may be caused by sex, but this does not mean it is an STI. If you have sex with another woman who has BV, you can also develop it. 

What are the symptoms of BV? 

The main symptom of BV is unusual vaginal discharge. This may have a strong, fishy smell and is often worse after sex. BV can also cause the colour or consistency of your discharge to change. This may mean your discharge becomes greyish, or watery. 50% of women who have BV do not have any symptoms at all. 

What is Thrush?

Thrush is a yeast infection, which is commonly found in the vagina. Thrush can affect both men and women, but is more common in women. It is usually harmless but can cause discomfort and may keep coming back. You can also get thrush in other parts of your body, such as your armpits, between your fingers, and your groin. 

What causes thrush?

Thrush is caused by a yeast called candida, which is a type of fungus that is usually harmless. Thrush can develop if this causes the balance of yeasts in your vagina to change. This can happens if you:

• are taking antibiotics
• have skin that is damaged or irritated
• have a weakened immune system
• are taking hormone replacement therapy (HRT)
• have poorly controlled diabetes
• are pregnant

Thrush is not an STI, but sex can trigger it. You can catch thrush if you have sex with someone else who has it, but this is uncommon. 

What are the symptoms of thrush?

The main symptoms of thrush in women include:

• itching or irritation around your vagina
• white vaginal discharge that looks like cottage cheese and does not have a smell
• stinging or soreness when you pee, or during sex

Sometimes thrush does not have any symptoms. 

How to tell the difference between thrush and BV

The most common difference between thrush and BV is the symptoms. Both cause unusual vaginal discharge, but it is more likely to be BV if the discharge has a strong, fishy smell. BV does not usually cause irritation or itching around your vagina, but thrush can. If you are unsure, you should speak to your doctor to get a diagnosis. 

How is BV diagnosed?

The best way to get BV diagnosed is to contact a doctor or a local sexual health clinic. Your doctor may ask you questions about your symptoms, to make sure it is not a different infection. 

You can also take a test which involves using a cotton bud to take a swab of your vagina, which is sent to a lab to test for BV and other infections. However if you have typical symptoms and are low risk for other causes your doctor may recommend treatment without any tests. 

How is thrush diagnosed?

If you are not sure if you have thrush, it is best to contact a doctor or visit a local sexual health clinic. A doctor may ask you about your symptoms to rule out any other infections and can provide treatment without any examinations or tests though sometimes they may also ask to look at the affected area. Thrush can also be diagnosed with a swab which will be taken by your doctor if needed. This is then sent to a lab to test for vaginal infections. 

Can you get tested?

Yes, if you have contacted a doctor and they are not sure, they may recommend that you do a test to confirm if you have thrush, BV, or another infection. You can also do a home test for thrush or BV, but it is best to speak to your doctor, especially if you have not had thrush or BV before. 

Can you have BV and thrush at the same time?

Yes, you can have BV and thrush at the same time. Your doctor will review your symptoms, which can determine which infection you have. If they are not sure, they can recommend a vaginal swab test, which can be tested for BV and thrush. It is uncommon to have both infections at the same time, but if you do, you can be treated for both. 

Is it more dangerous to have them both at the same time?

Thrush and BV are usually harmless, so having them both at the same time does not make it more dangerous. If you have BV, you are more likely to get an STI. The reason for this is not known, but it may be because it changes the acidity in your vagina which can reduce your natural defence against infections. You should get treatment if you have symptoms of thrush or BV, to reduce any risks. If you are diagnosed with BV in pregnancy you should chat to your midwife or doctor to make sure you get treatment.

How can I tell if I have both or just one?

The best way to tell if you have BV or thrush is by speaking to a doctor. They will be able to look at your symptoms and diagnose the infection. They may also recommend a test to check if you have one, or both. Usually, if you have itching and irritation, you are more likely to have thrush than BV. If your discharge smells and is watery and grey, you are more likely to have BV. If you have the tell-tale symptoms of both infections, it is possible you have both thrush and BV at the same time.

How are BV and Thrush treated?

While some of the symptoms may be similar, BV and thrush are treated in different ways. This is why it is important to know which infection you have before you start treatment.

How is BV treated?

BV is a bacterial infection, which means it can be treated with antibiotics. However, this is only recommended in women who have BV symptoms. If you are pregnant, or planning an abortion, treatment is recommended even if you don’t have symptoms. You can choose whether you want to take tablets by mouth, or use a gel or cream which can be inserted into your vagina. 

Metronidazole is a common antibiotic used to treat BV. This can be found in the form of metronidazole tablets or metronidazole gel. The gel is commonly available under the brand name of Zidoval. If you prefer to use a vaginal cream, we can also provide Dalacin cream, which contains the antibiotic clindamycin.

Metronidazole can be taken as a 1 day, or 7 day course of tablets. Dalacin cream should be used for 7 days and Zidoval gel is used for 5 days. Your doctor will discuss your treatment in more detail if you have symptoms that are consistent with BV and the treatment is suitable for you. 

How is thrush treated?

Thrush is commonly treated with an antifungal medicine called clotrimazole, which is found under the branded name Canesten. Fluconazole is another antifungal medicine that can be taken by mouth to treat thrush.

Clotrimazole is available as Canesten cream, which is applied to the outside of the vagina, or Canesten Combi, which contains the cream and one pessary. The pessary needs to be inserted into your vagina at night. The cream can be used 2 to 3 times a day.  

Canesten Duo is another option, which contains one fluconazole tablet to be taken by mouth, as well as clotrimazole cream to soothe external symptoms.

How to prevent BV and thrush

There are lifestyle changes you can make to help prevent BV and thrush, but if you do get a vaginal infection, you need to take your treatment if it is prescribed, to stop the infection from coming back. Some women are more likely to get thrush or BV again, which is known as a recurrent infection. Speak to your doctor if you get BV or thrush that keeps coming back. 

How to prevent BV

To help prevent BV and relieve its symptoms, you can:

• take showers instead of baths
• avoid using perfumed soaps, shower gel, shampoo, or bubble bath
• only use water and plain soap when washing your genital area
• stop smoking
• avoid using strong washing detergents to wash your underwear
• avoid putting antiseptic liquids in your bath
• not use vaginal douches, washes, or deodorants
• avoid sex until you have finished treatment

How to prevent thrush

There are certain things you can do to help prevent thrush and relieve its symptoms if you have it, such as:

• drying your groin properly after washing
• using water and emollient, such as E45 cream, instead of using soap on the affected area
• avoiding sex until your thrush has gone
• wearing cotton underwear
• not using soaps or shower gels on your vagina
• avoiding vaginal deodorants or douches
• not wearing tight pants or underwear

Sources

Bacterial vaginosis (2018) NHS (accessed 25 October 2021)

Bacterial vaginosis: What factors contribute to the development of bacterial vaginosis? (2018) NICE [Accessed 29 November 2021]

Candida - female genital: What are the risk factors? (2021) NICE [Accessed 29 November 2021]

Clotrimazole (2019) NHS (accessed 25 October 2021)

Metronidazole (2018) NHS (accessed 25 October 2021)

Thrush in men and women (2020) NHS (accessed 25 October 2021)

Vaginal discharge (2021) NHS (accessed 25 October 2021)