BBT tracking for Cycle Comprehension
Why am I asking you to record your temperature every morning?
What does your monthly basal body temperature (BBT) chart tell us?
Basal body temperature (BBT) tracking is a simple yet powerful tool in deeply understanding your menstrual cycle, fertility, and overall hormonal health.
What is BBT?
BBT is your body’s lowest resting temperature, taken first thing in the morning upon wake. Before ovulation, temperatures typically fluctuate around 35.9-36.4°C. Post-ovulation, BBT should rise around 0.3-4°C and remain elevated until your next bleed.
Ovulation occurs the day before your temperature rise.
Why does BBT change?
BBT shifts in response to your reproductive hormones.
Follicular phase: estrogen is dominant, temperatures are on the lower side
Luteal phase: ovulation triggers progesterone release, which has a warming effect, raising your BBT until menstruation
Why is BBT important?
BBT is one of the most reliable methods to confirm ovulation has occurred! When we see a few consecutive higher temperatures, ovulation will have occurred before the first high temperature. Tracking the timing of ovulation is helpful for those trying to conceive, avoiding conception, coming off hormonal contraception, and understanding irregular cycles.
BBT charts can reveal:
- anovulatory cycles (no ovulation occurs) - short follicular/luteal phase
- hormonal imbalances
- thyroid issues
How do I track my BBT?
Acquire a thermometer which measures to the hundredths place (0.01°C)
Measure: every morning, immediately upon waking, before getting out of bed/talking/drinking water, checking your phone.
Ideally it is roughly the same time every day, using the same method and thermometer. Record.
How we interpret your chart
We are looking for patterns, especially over several months. Ideally, there are lower temperatures before ovulation, a clear rise, and a sustained higher temperature in the luteal phase.
Many factors can influence temperatures, so fluctuations are completely normal - poor sleep, illnesses, alcohol/arguments the night before, travel, stress, and more.
BBT through a Traditional Chinese medicine lens
I also assess your charts through traditional Chinese medicine principles
They will help us understand:
- Yin/Yang deficiencies
- Qi or Blood stagnation (source of pain)
- Empty or Full Heat (hot sensations with or without a high temperature)
- the pivot of Yin to Yang at ovulation
- deeper constitutional imbalances
This information can further strengthen your diagnosis, guide herbal prescriptions (sometimes phase specific), confirm ovulation, and bring clarity to complex or irregular symptoms.
BBT is a modern mirror of TCM diagnosis - just quantified.
