Home Thyroid Test

The Barnes Basal Temperature Test is a simple test that anyone can do at home to see if they may have hypothyroidism. All you need is a thermometer. (Make sure it is a thermometer that has mercury in it.) Your body temperature reflects your metabolic rate, which is largely determined by hormones secreted by the thyroid gland.

1. Shake down the thermometer to below 95 degrees the night before you take the test and place it by your bed within easy reach. The idea is to move as little as possible before taking your temperature, while you're calm and almost asleep.

2. After waking up, moving as little as possible and not getting out of bed, place the mercury bulb of the thermometer in the center of your bare armpit and place your arm by your side. Leave the thermometer there for a full 10 minutes.

3. After 10 minutes, record the temperature, time and date.

4. Record the temperature for at least three mornings at the same time each day, if possible. Menstruating women should start recording temperatures on the second day of menstruation.

5. Add up all temperatures and divide by three to get the average temperature.

6. Your basal body temperature should be between 97.6 degrees F and 98.2 degrees F. Anything lower than that can indicate hypothyroidism and anything higher can indicate hyperthyroidism.