How is bacterial vaginosis diagnosed?
The typical discharge and its characteristic fishy smell make bacterial vaginosis (BV) likely. If you are in a stable, long-term relationship, your doctor or nurse may be happy to diagnose BV just by its typical symptoms. However, there are some tests available that can help to confirm the diagnosis. Also, if you are pregnant, it is important to make an accurate diagnosis if you have vaginal discharge so that any infection can be treated effectively. This will mean having one or more of the tests below.
Testing the acid level of your vagina
The discharge of BV has a typical pH level (acid/alkaline balance) compared to other causes of discharge. (The overgrowth of the germs (bacteria) of BV causes the pH to change in the vagina so that it becomes more alkaline, ie the pH rises.) If available, your doctor or nurse may suggest that they take a sample of your discharge and test it with some pH paper. In addition, if an alkali is added to a sample of the discharge, it often causes a characteristic fishy smell.
You can also buy a kit from a chemist to do this test yourself at home.
Taking a sample (a swab)
To confirm the diagnosis, your doctor or nurse may also suggest that a swab of your discharge be taken from your vagina and sent to the laboratory for testing. Large numbers of various bacteria that occur with BV are seen under the microscope. Your doctor or nurse may suggest that they take more than one swab from your vagina to rule out other causes of vaginal discharge.
Did you find this information useful?
- Management of bacterial vaginosis; British Association for Sexual Health and HIV (May 2012)
- Bacterial vaginosis; NICE CKS, July 2014 (UK access only)
- Brotman RM, Ghanem KG, Klebanoff MA, et al; The effect of vaginal douching cessation on bacterial vaginosis: a pilot study. Am J Obstet Gynecol. 2008 Jun 198(6):628.e1-7. Epub 2008 Mar 4.
- Oduyebo OO, Anorlu RI, Ogunsola FT; The effects of antimicrobial therapy on bacterial vaginosis in non-pregnant women. Cochrane Database Syst Rev. 2009 Jul 8 (3):CD006055. doi: 10.1002/14651858.CD006055.pub2.
- Brocklehurst P, Gordon A, Heatley E, et al; Antibiotics for treating bacterial vaginosis in pregnancy. Cochrane Database Syst Rev. 2013 Jan 31 1:CD000262. doi: 10.1002/14651858.CD000262.pub4.
- Sexually Transmitted Infections in Primary Care; Royal College of General Practitioners and British Association for Sexual Health and HIV (Apr 2013)
- Senok AC, Verstraelen H, Temmerman M, et al; Probiotics for the treatment of bacterial vaginosis. Cochrane Database Syst Rev. 2009 Oct 7 (4):CD006289.
- Evans AL, Scally AJ, Wellard SJ, et al; Prevalence of bacterial vaginosis in lesbians and heterosexual women in a community setting. Sex Transm Infect. 2007 Oct 83(6):470-5. Epub 2007 Jul 4.
- Vaginal discharge; NICE CKS, May 2013 (UK access only)
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.