Bacterial vaginosis 


Vagina health

Find out about vaginas, from keeping clean and healthy to what's normal and what's not. Includes changes after childbirth

Bacterial vaginosis (BV) is a common yet poorly understood condition in which the balance of bacteria inside the vagina becomes disrupted.

BV does not usually cause any vaginal soreness or itching, but it often causes unusual vaginal discharge. If you have the condition, your discharge may:

  • develop a strong fishy smell, particularly after sexual intercourse
  • become a white or grey colour
  • become thin and watery

BV is not serious for the vast majority of women, although it may be a concern if symptoms of BV develop in pregnancy and you have a history of pregnancy-related complications.

Around half of women with bacterial vaginosis have no symptoms. In these cases, the condition does not pose any threat to your health or pregnancy.

When to seek medical advice

See your GP or visit a sexual health or genitourinary medicine (GUM) clinic if you notice any abnormal discharge from your vagina, especially if you are pregnant. It is important to get this checked to rule out other infections and prevent complications.

Your doctor will ask you about your symptoms and they may examine your vagina. In some cases, a small sample of the vaginal discharge will be taken using a plastic loop or swab so it can be examined for signs of BV.

Read more about diagnosing bacterial vaginosis.

Why it happens

The vagina naturally contains a mix of many different bacteria. In cases of BV, the number of certain bacteria increases, affecting the balance of chemicals in the vagina.

What leads to these changes in the levels of bacteria is not clear. BV is not classified as a sexually transmitted infection (STI), but you are at a higher risk of developing the condition if you are sexually active.

Women with BV may be able to pass the condition to other women they have sex with, although it is not clear how this happens.

There is no evidence to suggest that the bacteria causing BV can affect male sexual partners.

There are also a number of other factors that can increase your risk of developing BV, including using scented soaps or bubble baths, having an intrauterine device (IUD) fitted and using vaginal deodorant. BV is more common in women who use a coil for contraception and those who perform vaginal douching (cleaning out the vagina).

Read more about the causes of bacterial vaginosis.

Treating bacterial vaginosis

BV can usually be successfully treated using a short course of antibiotic tablets or an antibiotic gel that you apply inside your vagina.

In most cases, you'll be prescribed antibiotic tablets to take twice a day for five to seven days.

However, it is common for BV to recur. More than half of women successfully treated with BV will find their symptoms return, usually within three months. Women who have frequent episodes of BV may be referred to a genitourinary medicine (GUM) specialist.

Read more about treating bacterial vaginosis.


If BV develops in pregnancy it may increase the risk of pregnancy-related complications, such as premature birth or miscarriage. However, this risk is small and appears more significant in women who have had these complications in an earlier pregnancy. BV causes no problems in the great majority of pregnancies.

As a precaution, you should contact your GP or GUM clinic if you are pregnant and you begin to have vaginal discharge (although discharge can be a normal part of pregnancy).

Bacterial vaginosis can also increase your risk of getting some STIs.

Read more about the complications of bacterial vaginosis.

Preventing bacterial vaginosis

The causes of bacterial vaginosis are not fully understood, so it is not possible to completely prevent it. However, you may be able to lower your risk of developing the condition if you avoid:

  • using scented soaps, perfumed bubble bath and antiseptic bath liquids
  • using vaginal deodorant
  • vaginal douching
  • using strong detergents to wash your underwear

These can upset the natural bacterial balance in your vagina, making it more likely that you will develop BV.

Page last reviewed: 03/10/2013

Next review due: 03/10/2015


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The 9 comments posted are personal views. Any information they give has not been checked and may not be accurate.

bubbles01 said on 07 November 2013

I went to the Doctor thinking I had a repetition of thrush however he told me I had BV and thrush.

He gave me Metronidazole for the BV, and said that it is from excessive washing and most commonly using soap. Apparently when the BV or thrush flares up you shouldn't wash (my first instinct) as its like putting petrol on a fire.

Doctor told me to buy Dermol 500 to wash with instead.

He gave me thrush cream with a pessiry for the itching.

Also I know its been mentioned below but he strongly advised no drinking on the anitibiotics as they will make you violently sick!!

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autumn treasure said on 06 October 2013

Ladies the best thing to do is determine if it's BV or trick they both hAve fishy discharge and odours

I had 7 courses of metronidazole 3 courses of Saladin then I watched embarrassing bodies immediately visited my gp and asked for balance Activ gel or pessaries (also available over the counter prescription is cheaper) and I haven't had BV back I recently had my 12th swab and I'm clear for the first time In two years

I use one pessarie every third day which is why I get it on prescription it really does work

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Meechie said on 18 June 2013

First, you should never dismiss any vaginal changes without getting a GYN involved. I used to constantly suffer from BV with only 1 sex partner. It wasnt until I became prego that my OBGYN (30+ years of experience) advised me that I was actuallly HPV positive and that I could get cervical cancer if left untreated. Not sure how long I already had it but, This was the wakeup call! After having a biopsy and treatment, I came back 3 mos later HPV negative thank God! And has had no reccurrences with BV.... With that he advised me that simple vitamin C will keep my vaginal bacteria good and balanced...So stop spending all that money on unnatural products....Be Healthy! And see your doctor often

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just_a_girl said on 19 April 2013

Have had this twice now and have cleared it up both times very quickly by using the herb Goldenseal.
It's available from health food shops. I buy the capsules with the ground up powder in.
I break one open and put the powder in a container with about 90 ml boiling water. Let it cool right down. Strain out the powder and get rid of it, then douche with the liquid solution.
Did this the other day after having a BV flare up from wearing so many layers of clothes throughout winter (I work outdoors so I wear tights and trousers and sometimes waterproofs on top as well, plus wearing pjs in winter to keep warm at night - the extra heat causes BV for me).
Two applications over 3 days and the problem was gone.
Definitely worth a try!
The tablets are also good for if you have heavy periods as well (depending on the cause of course).

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autumn treasure said on 08 January 2013

Bv can be caused by soap, i kept getting it every time i used soap (including femfresh) my gp then gave me a prescription for dermol 500 (soap substitute) i havent had it again since

# dont douche with soap
# bath tub and half a cup of salt weekly in a bath kills bad bacteria
# wear cotton knickers as this allows your intimate area
To breathe
# dont sleep with any bottoms or pants on
# sperm can be very alakline and cause death to natural bacteria
# boil underwear in boiling water (or buy new ones) to rid any chance of getting the infection back
# Bacterial vaginosis is sexually trabsmittable between women to women but not woman to man
# wash underwear at 50 degrees as well as bedsheets

# balance activ is a gel available from pharmacists this can helo too
This should prevent any further problems

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Alice13 said on 17 July 2012

I've been on Microgynon 30 for about six or seven months, but I've had clear or yellowish unpleasant-smelling vaginal discharge since before that and before I was sexually active. BV is the condition my symptoms seem most closely to fit, but the discharge has never been greyish. However, it does appear most after sex, but again it's not grey. Before I've just dismissed it as an inconvenient but natural occurrence and dealt with it by using daily liners, but now I'm wondering if it is BV - has anyone else experienced the same thing? Is it worth trying Metronidazole just to see if it helps?

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pavlova said on 17 November 2011

ive got my horrible bv back again !! and my fella has complained he has a sore on his penis ... can bv do this ?? and whats the treatment for him please ?
ive got my metronizadle and cream . do i just give him the cream .

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essexgal said on 22 July 2011

lately my discharge has been thicker, more often and occasionally smells fishy. could i have BV or thrush? and what do i need to do about it? it's putting me off having sex with my boyfriend and allowing foreplay to me because if i can smell it then surely he can...i'm 16 and i know it's not an sti because me and my boyfriend have been checked out, i just want the problem to have an answer!

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londonsquirrel said on 30 June 2011

Since having a Mirena IUS fitted one year ago I have suffered from recurrent BV (diagnosis confirmed by swab test). I have been treated with courses of antibiotics and more recently with Metronidazole vaginal gel. The latter has proved invaluable, as it rids me of the BV (without the side effects experienced when taking antibiotic tablets). Unfortunately after either course of treatment, the BV returns after only a few days.

I have recently been informed that there is a manufacturing/supply problem with the Metronidazole gel and I am unable to obtain any further supplies (I have tried all the pharmacies in my area - none left in stock). My GP says that there is no similar product that could be substituted. Meanwhile my BV is going untreated and I am suffering discomfort and feeling self-conscious. Please, please, can anyone help?

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