Bacterial vaginosis

Summary

Bacterial vaginosis (or BV) often has no symptoms, but can cause a watery, white or grey vaginal discharge with a strong smell.
Bacterial vaginosis may be caused by having sex. However, it is still yet unknown whether it is transmitted from person to person via sex.
Bacterial vaginosis is usually treated with antibiotics (either tablets or a vaginal cream).

About bacterial vaginosis (BV)
Symptoms of bacterial vaginosis (BV)
Possible causes of bacterial vaginosis (BV)
Diagnosis of bacterial vaginosis (BV)
Treatment for bacterial vaginosis (BV)
Vaginal cream for bacterial vaginosis (BV)
Bacterial vaginosis (BV) reinfection
Preventing bacterial vaginosis (BV)
Where to get help

About bacterial vaginosis (BV)

Illustration of the female reproductive system labelling ovary, fallopian tube, uterus, cervix and vagina.

It is normal for a healthy vagina to have many types of bacteria present.

Bacterial vaginosis (or BV) is common. It is caused by an imbalance of the bacteria normally present in the vagina. In people with BV, the normal healthy bacteria (in particular, lactobacilli) are replaced by an overgrowth of other mixed bacteria.

The exact cause of BV is unknown.

Symptoms of bacterial vaginosis (BV)

Symptoms of BV may include:

a change or increase of discharge from the vagina
a strong or unusual odour from the vagina (often described as a ‘fishy smell’)
vaginal discomfort and/or itch.

Bacterial vaginosis may occur at the same time as sexually transmissible infections (STIs).

Possible causes of bacterial vaginosis (BV)

Although the causes of bacterial vaginosis are unknown, BV may be associated with:

a change in sexual partner
having a sexual partner who has a vagina
not using barrier methods (such as internal and external condoms) consistently
douching (washing the inside of the vagina).

Research has not conclusively found a link between BV and specific sexual practices or acts. However, recent evidence supports the use of condoms to reduce the risk of this infection.

Diagnosis of bacterial vaginosis (BV)

Diagnosis of BV is made based on signs and symptoms and lab tests. During a medical examination, your doctor may notice:

a lot of vaginal discharge
odour from the vagina
decreased acidity of the vaginal fluid on pH testing.

Treatment for bacterial vaginosis (BV)

If you have no symptoms, treatment for BV is usually not required. BV is 'self-limiting' (meaning it will go away by itself).

Many people with BV do not experience complications. However, BV has been linked with early pregnancy loss (miscarriage), premature labour and low infant birth weight. BV has also been associated with pelvic inflammatory disease (PID) and increased risk of getting a sexually transmissible infection (STI).

Seek treatment if:

You are about to have a medical procedure that could allow bacteria into the uterus (for example, insertion of an IUD, or termination of pregnancy).
You are pregnant – talk to your GP, obstetrician or midwife about treatment for BV.
Symptoms of BV are affecting your quality of life and you are avoiding sex because of it.

Prescription medication for bacterial vaginosis (BV)

An antibiotic (tablet) called metronidazole can be used to treat BV. If your doctor prescribes metronidazole you will need to:

Take the antibiotic twice a day for 7 days.
Take the tablets after meals – this can reduce the nausea and upset stomach that is sometimes associated with this medication.
Avoid drinking alcohol while taking this medication.

Vaginal cream for bacterial vaginosis (BV)

Doctors can also prescribe a vaginal cream (such as clindamycin) if you are unable to take metronidazole. Clindamycin is applied to the vagina for 7 nights.