I. What is basal body temperature? Basal body temperature (BBT) is the body temperature of the body in the most basic activity, which reflects the energy metabolism level of the body in the resting state, so it is also called resting body temperature. What is the significance of measuring basal body temperature? During the menstrual cycle, the basal body temperature varies periodically with the amount of estrogen and progesterone secreted at different times. In adult women, after ovulation, progesterone is produced by the formation of the corpus luteum, which has a thermogenic effect and stimulates the thermoregulatory center in the lower thalamus, thus causing the basal body temperature to rise by 0.3~0.5℃, so the basal body temperature rises after ovulation and then falls again 1~2 days before menstruation or on the first day of menstruation. Therefore, in a normal menstrual cycle, a biphasic curve is drawn by drawing a line with the temperature measured every day. Continuous measurement of basal body temperature can help us understand the basic information of follicular phase, ovulation phase and luteal phase of menstrual cycle, which is an important test for the diagnosis and treatment of infertility, sterility (including miscarriage, stillbirth and premature birth), menstrual irregularities (including gongbao and amenorrhea), etc. It also has 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 will be the thermometer mercury column dumped below 35 ℃, and will be placed on the bedside table or pillow side, reach out to the place, the next morning after waking up, do not talk, do not get up, do not move (including not drinking, eating) will be prepared the day before the thermometer under the tongue, shut up, measurement 3 ~ 5 minutes. Usually measured at 5~7 a.m.; 2. Remove the thermometer to take a reading at the time; 3. Draw dots on the special basal body temperature form with the readings and connect the dots with a connecting line to come up with a curve. If to the next menstrual cycle, start the next chart from the beginning; 4, on the day of having sex in the points plus; 5, in the menstrual period under the points plus w; 6, the day there is a cold, insomnia and other diseases, factors that may affect the temperature, must be marked in writing so that you can always refer to; 7, generally need to be measured continuously, at least 3 menstrual cycles or more. IV. What are the points to note for measuring BBT? 1.Night 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, long term habit of night life, waking up late in the morning or measuring the temperature after sleeping during the day is also inaccurate. Night shift workers should be measured in the daytime after 6 to 8 hours of rest, just after waking up; 2. The time of measurement must be fixed (this point is generally not stated in the book, but in fact is very important), if measured at 6:00 am the day before, then every day thereafter need to be measured at the same time, and the error before and after is best within 15 minutes. We found in the long-term observation, the earlier the measurement time the lower the temperature, the later the measurement time the higher the temperature, if the time error of two days of measurement more than half an hour, the temperature will have greater fluctuations, will affect the accuracy of the judgment.