Usually, the leucorrhoea is milky white slightly sour smell may be normal, if there is obvious sour smell, it suggests the possibility of vaginal inflammation, but not necessarily, need to judge the cause according to different situations.1, normal metabolism: if daily attention to cleanliness and no vulva itching, urethral red pain and other discomfort, it may be normal situation, because the vaginal epithelium of women of childbearing age contains glucose, vaginal Lactobacillus will use glucose to produce lactic acid to maintain a normal acidic vaginal environment to inhibit the growth of miscellaneous bacteria, so it is normal to have a little sour smell; and the normal color of leucorrhea is white thin paste or egg white; so leucorrhea is milky white with a sour smell may also be normal physiological metabolism, do not worry too much; 2. If the leucorrhea is still milky white but beanbag-like, or sour smell is obvious, there is a possibility of vaginal inflammation, usually accompanied by vulvar itching, burning discomfort in the vagina, etc. The cause can be determined by vaginal discharge examination. It is important to pay attention to personal hygiene and lifestyle habits, such as rinsing the vulva with water in the shower, avoiding repeated vaginal irrigation, frequent sexual intercourse, and wearing tight and non-breathable underwear.