Leukorrhea is a vaginal secretion. Vaginal secretions are a mixture of different substances from different parts of the female reproductive system, such as secretions from the vestibular glands, cervical glands, endometrium, and exudate from the vaginal mucosa, and detached vaginal epithelial cells, commonly known as leukorrhea. Leukorrhea is divided into physiological and pathological, pathological leukorrhea is often manifested as leukorrhea abnormality, in daily life if pathological leukorrhea scarcity also need to go to the hospital as early as possible for examination and diagnosis. Examination To check whether the leukorrhea is normal, we should observe from the quantity, color, texture and smell. 1, gynecological examination The examination is carried out sequentially from the outside to the inside. Firstly, the vulva, urethra, para-urethral glands and vestibular glands are examined through visual inspection, and secondly, the walls of the vagina and the cervix are observed through a vaginal speculum. Check the appearance of vaginal discharge and cervical secretion. 2.Laboratory examination (1) pH value: pH is 3.8-4.4 when normal, the pH value of leukorrhea rises when suffering from trichomonas or bacterial vaginitis. (2) Vaginal cleanliness: Ⅲ degree: a small number of vaginal bacilli are seen under the microscope, and there are a lot of pus cells and bacteria. Degree IV: no vaginal bacilli are seen under the microscope, except for a small number of epithelial cells, mainly pus cells and miscellaneous bacteria. Degree III to IV is abnormal leukorrhea, indicating vaginal inflammation. The Ⅰ～Ⅱ degree is normal. (3) Molds and trichomonas: If trichomonas or molds are present, regardless of the number of trichomonas or molds, they are indicated by “+”, and the symbol “+” only indicates that the woman is infected with trichomonas or molds, and does not indicate the severity of the infection. Differential diagnosis 1, cheese-like leukorrhea or tofu scum-like leukorrhea: mycosis vaginalis, often accompanied by severe vulvar itching or burning pain. 2, thin purulent, yellowish-green, foamy, foul-smelling leukorrhea: the characteristics of trichomonas vaginitis, accompanied by vulvar itching. Grayish-white, thin, fishy-smelling leukorrhea: characteristic of bacterial vaginosis, accompanied by mild vulvar itching. 4.Purulent leukorrhea: yellow or yellow-green in color, sticky and thick, mostly with foul smell, caused by bacterial infection. It can be seen in Neisseria gonorrhea vaginitis, acute cervicitis and cervicocervicitis. Vaginal cancer or cervical cancer with infection, pus in the uterine cavity or foreign body residue in the vagina can also lead to purulent leukorrhea. Pus and blood leukorrhea: consider acute pelvic infection, cervical cancer, vaginal cancer with infection, accumulation of pus in the uterine cavity, foreign body in the vagina and so on. 6.Watery leukorrhea: thin as watery or rice slop with fishy odor vaginal discharge: seen in advanced cervical cancer, vaginal cancer or submucous membrane leiomyoma with infection. Intermittent discharge of clear, yellowish-red or red watery leukorrhea should be considered as the possibility of fallopian tube cancer. Bloody leukorrhea: if there is blood mixed with leukorrhea and the amount of blood varies, cervical cancer, endometrial cancer, cervical polyp, cervical columnar epithelial ectasia combined with infection or uterine submucosal leiomyoma should be considered. The placement of intrauterine device can also cause bloody leukorrhea.