If you think you have this infection, you should visit a genitourinary medicine clinic for treatment and to be checked for other infections.

Usually, the doctor will look at the vulva for any signs of thrush, and will then insert a hollow plastic or metal tube (speculum) into the vagina, in order to look at your vagina (rather like having a smear).

Each cause of vaginal discharge has its own proper treatment, which could be a cream or tablet, and it is important to follow the treatment instructions from your doctor or the clinic very carefully.

If you are asked to return for another check-up, it is important that you do so, even if the discharge has gone.

When this discharge is exposed to the air, it becomes brownish-yellow, so it is normal to find a yellowish stain on your knickers in the middle of the monthly cycle.

There may also be a feeling of moistness and stickiness.

It causes a discharge that is often frothy and yellowish-greenish, but it may be thin and scanty.