Definition

Basal body temperature is your body's lowest resting temperature, measured immediately upon waking before any activity. Tracking BBT throughout the menstrual cycle reveals ovulation—temperature rises 0.5–1°F after ovulation due to progesterone. BBT charting helps identify fertile windows, confirm ovulation, and assess luteal phase adequacy.

Why It Matters

BBT tracking is a free, non-invasive method to confirm ovulation, identify fertile days for conception, detect luteal phase defects, and understand cycle patterns. While not precise for predicting ovulation in real-time, it's valuable for understanding your unique cycle and supporting fertility awareness.

Related Conditions

Infertility Support Pcos Amenorrhea Luteal Phase Defect

Related Modalities

Lifestyle Medicine Clinical Nutrition

Frequently Asked Questions

Use a basal thermometer (measures to 0.1°F) and take your temperature orally immediately upon waking, before getting out of bed, at the same time each morning. Record daily on a chart or app. You'll see a biphasic pattern—lower temps before ovulation, higher temps after ovulation.

BBT confirms ovulation occurred but doesn't predict it in advance (temps rise after ovulation). For timing intercourse, use BBT data over several cycles to estimate ovulation day, then have intercourse in the days before expected ovulation. Combine with cervical mucus monitoring for best results.