Bacterial vaginosis (BV) is a common cause of unusual vaginal discharge. BV is not a sexually transmitted infection (STI), but it can increase your risk of getting an STI such as chlamydia.
Bacterial vaginosis is caused by a change in the natural balance of bacteria in your vagina.
What causes this to happen is not fully known, but you’re more likely to get it if:
- you’re sexually active (but women who have not had sex can also get bacterial vaginosis)
- you have had a change of partner
- you have an IUD (contraception device)
- you use perfumed products in or around your vagina
Bacterial vaginosis is not an STI, even though it can be triggered by sex.
A woman can pass it on to another woman during sex.
You’re more likely to get an STI if you have bacterial vaginosis. This may be because it makes your vagina less acidic and reduces your natural defenses against infection.