The pH value of urine, blood, saliva, etc. The normal range of pH value is between 7.35-7.45, which is the neutral state, less than 7.35 is the acidic state, and more than 7.45 is the alkaline state. The acidity and alkalinity of female leukorrhea is also described by the pH value. Under normal circumstances, the acidity and alkalinity of vaginal leukorrhea is not more than 4.5, which means that the vagina is in an acidic state, and the pH value will be detected during leukorrhea examination. If the pH value is simply elevated and there are no other clinical manifestations, you can consider whether you have had sexual intercourse in the 48h prior to the test of the leukorrhea, because semen or lubricating fluid of condoms will affect the pH value. It is important to pay attention to the timing of gynecological auxiliary examination, if the pH value is increased and the leukorrhea is abundant, yellow with odor, it is necessary to consider vaginitis, and it is necessary to combine the results of the examination to determine the type of vaginitis for treatment.