Even in the century before last, gynecologists noticed that women have a temperature during menstruation, and also shortly before their onset and at the end it changes. Moreover, these changes are not the same - before menstruation, it rises, and after their onset decreases.
Later, scientists found that the cause of the temperature change lies in the features of the endocrine system and ovaries. The most accurate indicator in this case is rectal temperature. This is explained by the fact that with the onset of menstruation, blood flow to the ovaries increases. On other parts of the body, changes in blood circulation are extremely rare. Sometimes the temperature is measured in the vagina. This method can also give the result of temperature fluctuations during menstruation.
The change in blood supply to the internal female genital organs is also due to the fact that during menstruation, an influx of hotter blood, saturated with nutrients and oxygen, is carried out to them. Especially intensively the blood rushes to the ovaries before the onset of menstruation, and therefore there is an increased temperature during menstruation. During menstruation, the blood is gradually depleted of oxygen, chemical processes are waning - and the temperature decreases. At the same time, hormones flow through the ovarian veins, which were synthesized there before menstruation.
Rectal temperature is best measured immediately after sleep, when the body is completely at rest. This temperature is called basal. In addition to the menstrual period, basal temperature also increases during ovulation and during pregnancy. In some cases, basal temperature can give inconsistent indicators when a woman, for example, is stressed or during long trips (business trips, vacations, etc.).
If basal temperature measurements are taken from the first days of menstruation, then its indicators can be approximately in the range of 36.5-36.7 degrees. Around the middle of the cycle, with the onset of ovulation, the temperature reaches 37 degrees, sometimes slightly higher. The phase of the menstrual cycle before ovulation is called follicular. In this elevated state, the temperature during menstruation can stay until the next cycle. This phase is called luteal. With the onset of menstruation, body temperature gradually decreases.
Thus, from this short overview of the menstrual cycle, it is clearly visible that the temperature measured in the vagina or in the rectum rises in the period before menstruation, then it decreases after they occur.
Sometimes the temperature during menstruation does not change, that is, there is no decrease in indicators, which is mainly due to pathology. When menstruation is accompanied by pain, the temperature can stay elevated for some time after the onset of menstruation.
The main reason for the condition when the temperature is high during menstruation is endometriosis, when pain and an increase in degrees can be observed throughout menstruation. With endometriosis, inflammation of the uterine mucosa occurs, which explains the increase in temperature indicators.
Another reason when the temperature after the onset of menstruation does not decrease, but goes up, may be a pregnancy with minor discharge. When pregnancy occurs, as with ovulation, the temperature will inevitably increase during menstruation. And if there is any pathology, then the pregnancy is accompanied by bloody discharge, and in the first month a woman can take this for a false menstruation.
If a woman is healthy and pregnancy has not occurred, then by observing the basal temperature, you can accurately predict the onset of menstruation. This may be necessary in case of an unstable cycle or when planning any events (trip, holiday, etc.), especially if a woman feels a slight malaise during menstruation. So, when an elevated temperature is detected, a woman can determine that the menstrual cycle is in a second phase state, and when it decreases, that menstruation is about to begin. For this, basal temperature must be measured regularly and only at rest. Having well studied her menstrual cycle and especially the state of her body during menstruation, a woman can be confident in her health.