Symptom Checker

Understanding BV

By Helen Knox, Clinical Nurse Specialist in Contraception and Sexual Health

If you want to succeed in treating your BV (bacterial vaginosis) and stop it from coming back, it’s important that you understand what BV is, and what can trigger it.  Although all women have one, many of us don’t really know what’s going on inside a vagina! A little understanding can help us to keep this incredible part of our body healthy, by treating it correctly.

Your vagina is home to millions of micro-organisms, and most of the time they exist in perfect balance – a bit like a small eco-system.  The normal vaginal pH (“potential of hydrogen”, or acid-alkaline level) level is slightly acidic, thanks to the efforts of Lactobacillus, a good bacteria that produces lactic acid and bacteriocides to help keep any more harmful bacteria in check.   If we experience a decrease in these good bacteria, or a new strain of organism is introduced (such as an STI) and that causes an infection, you’ll probably start to see some unusual symptoms.

The bacterial balance inside your vagina is delicate and some of us are more prone than others to having the balance disrupted.  There are a number of things to be aware of that may upset your vaginal balance, leading to a bout of BV.  These include:

  • Perfumed or harsh ‘intimate washing’.  Your vagina is self-cleaning.  If all of your micro-organisms are in balance, there’s no need to meddle with it.  In fact, douching or using perfumed products down there can alter the natural balance with your vagina and actually cause BV.  This is sometimes a vicious cycle. With one of the most common symptoms of bacterial vaginosis being a fishy smell, women tend to reach for the perfumed washes or douches to try and get rid of that smell, but in doing so they are actually making the problem worse.   For this same reason, don’t add perfumed oils or soaps, or any ‘antibacterial’ or disinfectant products to your bath water.
  • Some women find symptoms of bacterial vaginosis are most noticeable after sex.  This is likely to be from having unprotected sex with a male partner since semen is alkaline and sometimes upsets that slightly acidic vaginal pH that your body needs to have.  If this is the case, you can try using a condom, or even going for a pee after sex can help.
  • Sometimes antibiotics themselves can trigger thrush and BV, by affecting both the harmful and the good bacteria, such as lactobacillus in the vagina.   While you’re taking antibiotics that affect you this way, it could be worth trying an acidifying gel, such as Balance Activ which helps to maintain the bacterial balance within the vagina, and encourages the good bacteria to grow.
  • Your period– sometimes prolonged periods can affect your normal vaginal pH balance, leaving you more vulnerable to developing BV.  If you do tend to get BV around the time of your period, try using a lactic acid gel during the last few days of the cycle before your period starts, and the last few days of your period itself, to try and prevent BV from occurring.

BV is the most common vaginal condition, and thought to be more prevalent than thrush, but it is often confused with that.  It’s important to understand your body and be able to identify the symptoms of these common conditions to make sure you get the right treatment to fix it.  As a rule of thumb:

  • BV – if you’ve got a fishy smelling discharge that’s thin and watery, possibly greyish, then you’ve probably got BV.
  • Thrush – if you’ve got intense itching, even burning, and / or a thick, curd like discharge, then you’ve probably got Thrush.


It is extremely important that the sexual infections, gonorrhoea and Chlamydia are ruled out before home treatment is considered. There is no point in seeking help if only half the investigations are carried out! So don’t be offended if you are offered such tests – they are offered routinely for your safety. And, in my experience, even when women believe they don’t have anything to worry about, they are happy to be screened, just to be sure.

When you are offered tests, you may be offered an internal examination so that the doctor or nurse can look at the type of discharge and check any other symptoms you may be noticing. They are likely to take a sample from the walls of your vagina, and if it’s a clinic that has a microscope, check it on site for the presence or lack of lactobacilli. Alternatively, they may take a different type of sample and send it to the laboratory for analysis. Laboratory test looks for various bacteria and if any are found and require treatment, the laboratory suggests the different antibiotics that the bacteria is sensitive or resistant to.

A simple way of looking at this is that the laboratory may, or may not suggest the standard metronidazole treatment, or perhaps a different antibiotic, or they may say that what they have found something that is not considered to be a problem bacteria. In normal circumstances the non-problem bacteria don’t need to be treated with anything but if the woman is pregnant, they may suggest treatment.

Once the woman knows what she is dealing with, and if antibiotics are not required or recommended, then home treatment may be the way she prefers to deal with it.

If you’re not sure about what you’ve got or think you need treatment, you should consult your healthcare professional for advice and get a definitive diagnosis rather than just assume you have one or the other of these annoyances.

Don’t be embarrassed, we have heard it all before, and then some! It’s really important to tell us what’s actually going on, what’s triggered it, what you’ve been using, washing with, adding to your bathwater or using to shower with, if you’ve been using: perfumed soaps, feminine sprays, wearing (thongs, tights, tight trousers etc.), whether your partner’s been ‘going down on you’ (especially whilst they have a sore throat), even what types of lubricant you’ve been using with sex toys and if you’ve been sharing them with your partner or partners. It’s also important to mention whether your partner just has sex with you, and you with them, or if you suspect or know otherwise… etc. etc! The more information you can give, the more ‘detective work’ that can be done to try and prevent your BV from recurring.

Your pharmacist, doctor, or GUM (Genito Urinary Medicine) or sexual health clinic will be able to provide you with advice.   If your condition doesn’t go away after home treatment it’s important to seek advice, as it may be a sign of an underlying condition or another type of infection. And, if you are 25 or over, it’s important to make sure your cervical smear tests are up to date. Abnormal cervical cell changes can also cause unusual vaginal discharge to occur.