Fast facts

  • Bacterial vaginosis is a common condition in women. Its main symptoms are greyish discharge and an unpleasant odour from the vagina.
  • It is caused by an imbalance of bacterial growth in the vagina.
  • It usually does not cause any long-term health issues.
  • Treatment can involve antibiotic medications.

Antibiotic

Chemical substances that kill or suppress the growth of bacteria.

What is bacterial vaginosis?

Bacterial vaginosis is a common vaginal infection in women. It occurs when there is an overgrowth of certain types of bacteria that are normally found in the vagina. This can result in a grey-coloured vaginal discharge. Some women with bacterial vaginosis may not experience any symptoms at all.

Bacterial vaginosis is not usually a very serious condition and is generally treated with antibiotics to help restore the vaginal bacteria to healthy state. 

Antibiotics

Chemical substances that kill or suppress the growth of bacteria.

Bacteria

Microscopic, single-celled organisms with DNA but no definite nucleus. Bacteria are the cause of many human diseases.

Signs and symptoms

The main symptoms of bacterial vaginosis include:

  • A greyish discharge from the vagina, and;
  • An unpleasant 'fishy' odour from the vagina.

Some women with bacterial vaginosis will not experience any symptoms at all.

Causes and risk factors

A healthy vagina is host to bacteria, especially Lactobacillus species. These bacteria produce lactic acid that keeps the vaginal area acidic, preventing other types of bacteria from growing there.

Bacterial vaginosis occurs when other types of bacteria, such as Gardnerella vaginalis, Mycoplasma hominis and Mobiluncus species, overgrow Lactobacillus.

It is not exactly clear what leads to this imbalance of bacteria in bacterial vaginosis. There are certain factors that can increase the risk of developing bacterial vaginosis, including:

  • Douching;
  • Cleaning the vagina with perfumed soaps and other cleansing products;
  • Having sexual intercourse with a new partner, and;
  • Having many sexual partners.

Although bacterial vaginosis is more common in sexually active women and sometimes develops after having sex with a new partner, bacterial vaginosis is not classified as a sexually-transmitted infection (STI), as it is not passed on through sexual activity.

Bacteria

Microscopic, single-celled organisms with DNA but no definite nucleus. Bacteria are the cause of many human diseases.

Douching

To wash or clean out with water or other solutions.

Sexually-transmitted infection

A viral or bacterial infection contracted through sexual intercourse or genital contact. Such an infection can lead to development of diseases such as chlamydia, gonorrhoea, genital herpes and AIDS.

Methods for diagnosis

To work out if you have bacterial vaginosis, your doctor may ask about any symptoms and perform a physical examination. They may take a sample of the vaginal discharge and send it to a laboratory to check the number and type of bacteria present and the pH (acidity) of the discharge. 

You may also be given tests to rule out other conditions that could be causing your symptoms.  

A vaginal swab is used to collect a sample of discharge for analysis. 

Bacteria

Microscopic, single-celled organisms with DNA but no definite nucleus. Bacteria are the cause of many human diseases.

pH

A measure of how acidic or basic a solution is.

Types of treatment

Cases of bacterial vaginosis that are do not cause any symptoms will not usually require treatment, unless there is a risk of complications from the condition.

If you have symptoms, your doctor may prescribe antibiotics, such as metronidazole, to treat the bacterial vaginosis and help restore the normal balance of bacteria in the vagina. In some cases a vaginal cream, such as clindamycin, may be prescribed. Creams are usually applied into the vagina using a device called a vaginal pessary.

Antibiotics

Chemical substances that kill or suppress the growth of bacteria.

Bacteria

Microscopic, single-celled organisms with DNA but no definite nucleus. Bacteria are the cause of many human diseases.

Vaginal pessary

A small and soft removable device that is inserted into the vagina to deliver medications and/or provide support to the female genital tract. Also known as a pessary or vaginal ring.

Potential complications

Having bacterial vaginosis during pregnancy increases the risk of premature birth (a baby born before 37 weeks' gestation) and delivering a baby with a low birth weight. Women who have bacterial vaginosis during pregnancy can be treated with antibiotics that are safe to take during pregnancy.

Antibiotics

Chemical substances that kill or suppress the growth of bacteria.

Prognosis

Bacterial vaginosis is usually not a serious condition. Some mild cases may go away on their own without any treatment, or resolve after antibiotic treatment.

Unfortunately, many people who are treated for bacterial vaginosis will develop the infection again within several months of treatment, but bacterial vaginosis does not usually cause any long-term health issues.

Antibiotic

Chemical substances that kill or suppress the growth of bacteria.

Prevention

As the exact cause of bacterial vaginosis is not known, there is no sure way to protect yourself from getting it. You may be able to reduce the risk by avoiding:  

  • Douching;
  • Using heavily perfumed soaps and other cleansers to clean the vaginal area, and;
  • Unprotected sex.

There is currently no evidence that treating a male sexual partner reduces the chance of developing the condition again. 

Douching

To wash or clean out with water or other solutions.