The most common cause is leucorrhoea, which is not a disease. The vagina is a moist cavity, and like the mouth, there are glands that produce the mucus that lubricates the vagina. If these glands become over active because of sexual stimulation, or taking oestrogen as a medication (eg. in the contraceptive pill or for symptoms of menopause), too much mucus will be produced, and overflow as a discharge. Some women produce more mucus than others, and may have long-term trouble with this type of loss.
Thrush is a fungal infection of the vagina caused by Candida albicans, and virtually every woman will have several episodes of this infection during her life. The fungus lives normally in the gut, but when there is moisture on the skin around the vagina and anus from sweating or sexual stimulation, the fungus can migrate into the vagina. Sexual intercourse helps the fungus into the vagina where it finds a nice warm, moist environment in which to live and prosper. The result is a white vaginal discharge that irritates the skin of the vulva, and creates an intense itch that is socially unacceptable to scratch in public.
A single-celled animal, Trichomonas vaginalis, may cause infections in a woman’s vagina, and the urethra (urine tube) of both men and women. The infection is transmitted by sexual intercourse. In women, the vaginal infection causes a foul-smelling, yellow/green, frothy discharge. There may be mild itching or soreness around the outside of the vagina.
Other possible causes include:
- oozing from a damaged or ulcerated cervix (particularly after childbirth),
- a forgotten tampon or other foreign body (particularly in little girls),
- an intrauterine contraceptive device (IUD),
- bacterial infections of the vagina (vaginitis),
- tumours or cancers of the cervix, vagina or uterus,
- pelvic inflammatory disease (widespread infection of the uterus and other organs within the pelvis),
- intestinal worms that migrate into the vagina,
- after an abortion, a coloured or smelly discharge is a serious sign that there may be an infection in the uterus.
A vaginal discharge in a young girl must be considered to be due to sexual abuse until proved otherwise. Infections and injury to the vagina are responsible.