Basal body temperature (BBT) is the lowest body temperature reached during sleep. It is typically measured upon waking, before any activity or food intake. Tracking BBT can be a helpful way to monitor ovulation and fertility, as it rises slightly after ovulation occurs. Checking BBT is a simple and inexpensive way to gain insights into your menstrual cycle and reproductive health.
BBT charting has been used for decades as a natural family planning method. By identifying the fertile window in the menstrual cycle, couples can plan intercourse to increase the chances of conception or avoid pregnancy. Additionally, BBT charting can be useful for diagnosing certain hormonal imbalances and disorders, such as polycystic ovary syndrome (PCOS).