Rather like the inside of your mouth and nostrils, the inside of your vagina is covered in mucous membrane – a type of body tissue that is naturally moist.
Having some amount of vaginal discharge is normal. Glands produce clear mucus that may turn white or yellow when exposed to air – also perfectly normal.
The amount of vaginal discharge varies during the menstrual cycle. This is due to the changing levels of estrogen circulating in your body. When estrogen levels are at their highest, discharge can become a bit heavier. Vaginal discharge can vary in consistency (thick, pasty or thin), color (clear, cloudy, white, yellow or green), and smell (normal, odorless or bad).
Vaginal discharge that suddenly changes in color, odor or consistency – even if it significantly changes in amount – may indicate an underlying problem like an infection. If this happens, see your doctor to get checked and treated if necessary.