Basal body temperature is used to monitor fluctuations in a woman’s monthly cycle and to determine how well the thyroid is working. Historically, one of the most consistent ways of assessing one’s thyroid function is by checking body temperature because this reflects the thyroid’s influence on the body’s metabolic rate. A basal body temperature that is consistently less than 97.8° F over a period of one month may indicate low thyroid function. Other tests, primarily blood tests, have been developed to check thyroid function. However, these values may come back normal even though symptoms of hypothyroidism are present.
Signs and symptoms of hypothyroidism include any of the following: dry or thinning hair, fatigue, dry skin, short nails with white spots, poor circulation with cold hands and feet, shivering spells, fluid retention, difficulty losing weight, slow digestion, constipation, mental tiredness, depression, poor memory, habitual headache that is usually worse in the morning, ringing in the ears, disturbed sleep, stiff joints, low/high blood pressure and a slow heart rate.
Measuring Your Basal Body Temperature
- Shake down the thermometer below 95°F, and place it beside the bed before going to sleep.
- On waking, place the thermometer under your armpit or in your mouth and rest for 5-10 minutes. The less movement you make, the more accurate the reading.
- Record your temperature on five different mornings. Record the date, temperature, and, for women, day of your menstrual cycle. Measure your temperature only during the first half (days 1 – 15) of your menstrual cycle. You may start on day 1 with the beginning of menses.
- Please bring your chart in with you to your next appointment.
This will aid us in determining if low thyroid function is contributing to your state of health.
 Hypothyroidism-The Unsuspected Illness, B. Barnes & L. Galton, 1976.
The information contained in this article is for information and education purposes only and is not medical advice. Do not use this information as an alternative to obtaining medical advice from your physician or other professional healthcare provider. Always consult with your physician or other professional healthcare provider about any medical conditions you are experiencing. If you are experiencing a medical emergency, contact your local emergency services for help.