I. Definition of basal body temperature (BBT) Basal body temperature (BBT) is the temperature of the body under the most basic activity, which is the temperature of the body after 6-8 hours of sleep, without disturbing factors such as exercise, eating and emotion. After ovulation in adult women, the progesterone produced by the corpus luteum of the ovary can stimulate the thermoregulatory center in the lower thalamus, causing the basal body temperature to rise by 0.3-0.5°C. Therefore, the basal body temperature rises after ovulation, and the high temperature phase is maintained for 11-14 days, until the temperature drops 1-2 days before menstruation or on the first day of menstruation. The accuracy of BBT in monitoring ovulation is 70%-80%. Continuous measurement of BBT is an important test for the diagnosis and treatment of infertility and menstrual disorders (including gonorrhea and amenorrhea), and has a certain guiding value for mastering safe contraception and finding the fertile period. How to measure the basal body temperature 1. Every night before going to bed, throw the mercury column of the thermometer to below 35℃, and put it in a place where you can reach it, such as on the bedside table or by the pillow. The next morning when you wake up, do not get up, do not talk, do not move (including not drinking or eating) immediately put the thermometer under the tongue for 5 minutes and then record the temperature on the temperature form. It is best to measure at 5-7 o’clock in the morning. 2, will read the body temperature in the special basic temperature table to draw points, and then connect the points with a line, resulting in a curve. 3.Add markers if you have sex. 4.In the menstrual period add w under the dot. 5, cold, fever, diarrhea, insomnia, alcohol, use of electric blankets, excessive alcohol consumption, late to bed and late to rise, etc. can affect the temperature, must be marked with text for reference. 6. It is best to measure the body temperature for 3 consecutive menstrual cycles. IV. What are the points to note for measuring BBT? 1. Nighttime sleep should be at least 6 hours, factors such as night shift or sleeping too late on a certain day can affect the accuracy of measurement. Night shift or third shift workers should be measured during the day after 6-8 hours of rest and just after waking up. 2. The time of measurement should be fixed. The earlier the measurement time the lower the temperature, the later the measurement time the higher the temperature, if the time error of the two-day measurement is more than half an hour, the temperature will have large fluctuations, which will affect the accuracy of the judgment. 3, the best use of mercury column thermometer.