Basal body temperature is used by western and Chinese medicine practitioners to track a woman’s menstrual cycle and ovulation patterns. This can be extremely useful for women attempting to become pregnant, as well as those trying to avoid pregnancy.
Beyond tracking menstrual cycles, western medicine doesn’t utilize basal body temperature for other medical reasons. However, in Chinese medicine basal body temperature has additional applications beyond tracking menstrual cycles. When paired with yin yang theory, it is used by Chinese medicine physicians to assess a patient’s overall reproductive health and to identify potential reproductive health issues.
What is a Person’s Basal Body Temperature and How is it Taken?
Basal body temperature refers to a person’s body temperature when they are at complete rest. You can think of this as your body’s baseline temperature – so any changes in this temperature likely indicates changes in bodily activity, such as entering ovulation.
When taking basal body temperature readings and comparing them, the recommendation is to do this in the morning, before getting out of bed or even doing something as simple as talking to someone else. Slight levels of activity are enough to influence body temperature and interfere with basal body temperature readings, so take your temperature readings first thing after waking up, ideally with a basal body temperature thermometer designed for the task.
What Do Changes in Basal Body Temperature Indicate?
Western and Chinese physicians monitor basal body temperature to track a woman’s menstrual cycle and ovulation period. Western physicians consider it relevant because as women move from one stage of the menstrual cycle to the next, their hormone levels fluctuate significantly. As hormone levels change, they influence other bodily functions that result in predictable, noticeable effects on basal body temperature.
For example, prior to ovulation, basal body temperatures tend to be lower. As a woman approaches ovulation, there will be a small drop in this temperature and then a sudden spike up following ovulation. This is usually an increase between 0.5 and 1 degree in basal body temperature, which isn’t much, but can be measured and detected. What is causing this? Western physicians believe it is changing levels of progesterone, which is involved in a large number of reproductive functions.
Basal Body Temperature From a Chinese Medicine Perspective
Chinese medicine practitioners also use basal body temperature to track a woman’s menstrual cycle, but the reason for doing so isn’t because of hormonal changes. Instead, basal body temperature is believed to be related to the patient’s balance of yin and yang energy – a primary concept in Chinese medicine that’s foundational to its medical philosophy.
In Chinese medicine, yin and yang are complementary, but opposing energies that drive the body’s essential functions. Each represents different aspects of life and the human body and keeping them in balance is essential. For example, yin energy is associated with the substantive, material elements of the body, such as its blood and other bodily fluids. Yang energy, by contrast, represents the animating energy that drives these bodily functions and supports life.
This theory is brought to bear when Chinese medicine practitioners use basal body temperature to track ovulation patterns.
Chinese medicine considers the ovulation cycle in four phases, including:
Phase one, the period and menstrual bleeding
During this stage, the yang energy is at its zenith and is beginning to transform into yin energy. This constant transformation from yin to yang and back to yin never stops and is replicated throughout the body during various functions.
Phase two, the follicular phase
During the follicular phase, the yin energy swells in prominence and grows in the body. And because both energies must remain in balance, yang energy levels are at their lowest during this part of the cycle. It’s also during this stage that cervical mucus builds up, which signals the start of ovulation and, according to Chinese medicine practitioners, is a sign that the substantive nature of yang is asserting itself.
Yin energy is also associated with rest and coolness, so it’s no surprise that basal body temperatures are lowest during this stage.
Phase three, ovulation
During ovulation, the yin energy is still rising and reaches its maximal level before it begins transforming into yang energy again. Practitioners believe this is the trigger that signals the ovaries to release the egg.
This is where the basal body temperature spike is seen, which makes sense, as yang energy is associated with heat and activity, and as it builds back up in the body, it influences temperature readings.
Phase four, the luteal phase
During this final stage, the yang energy continues growing and readies the uterus for egg implantation. And because yang is associated with warmth, basal body temperatures tend to remain higher until the beginning of the menstrual cycle again.
In addition to monitoring ovulation timing, Chinese medicine uses yin yang theory to assess a woman’s overall reproductive health as they pass through menstrual and ovulation cycles. For example, if there are signs of yin or yang deficiencies at any stage of the menstrual cycle, this could indicate health conditions that are interfering with the body’s ability to express either energy. This could be due to a variety of conditions, including premenstrual syndrome, PCOS, irregular and missed periods, painful periods (dysmenorrhea), ovarian cysts, fertility issues and others.
Basal Body Temperature Provides Valuable Information to Menstruating Women and Their Physicians
Basal body temperature is easy to take and track – it only takes a thermometer and a sheet of charting (or graph) paper to manage. It’s also extremely useful for tracking menstruation and ovulation – which is important for women seeking to become pregnant, or those trying to avoid it.
However, Chinese medicine considers basal body temperature in a larger context of yin yang theory that can be used for additional medical purposes, such as identifying issues with any part of the menstrual or ovulation process, as well as identifying underlying health conditions that could interfere with either.
If you are using basal body temperature to track pregnancy windows or menstrual cycles, a Chinese medicine practitioner will offer expert insight into what your temperature readings mean and how they can be used to improve your reproductive health.