It is normal to have some vaginal discharge, because the vagina stays moist as part of its self-cleansing mechanism. The normal moist discharge clears dead cells and bacteria from the vagina. It comes mainly from glands in the cervix (the neck of the womb), and is slightly acidic, which helps to keep infections at bay. The acidity results from lactic acid, formed by friendly bacteria as they break down sugars.
On average, a woman discharges from her vagina about 2 grams of dead cells and about 3 grams of mucus every day, but the amount of normal discharge varies from woman to woman, and with the menstrual cycle. Many women notice that, during the week following a period, there is hardly any discharge, and what there is has a thick consistency. Towards the middle of the cycle (about 2 weeks after the start of a period) the amount increases and it becomes thin, slippery and clear, like uncooked egg white. 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. Normal discharge does not smell, and does not cause any irritation or itching.
Discharge also increases during pregnancy. And during sexual excitement, vaginal discharge becomes very profuse because two glands near the vaginal opening (Bartholin's glands) secrete additional slippery mucus, which acts as a lubricant for intercourse.
What’s not normal
A discharge is likely to be abnormal if:
• it smells fishy
• it is thick and white, like cottage cheese
• it is greenish and smells foul
• there is blood in it (except when you have a period)
• it is itchy
• you have any genital sores or ulcers
• you have abdominal pain or pain on intercourse
• it started soon after you had unprotected sex with someone you suspect could have a sexually transmitted infection.