Your temps will fluctuate during the day. The basal body temp used for comparison is your temp first thing waking up, taken as you lay in bed.
From Stop The Thyroid Madness:
"HOW DOES MY TEMPERATURE DIAGNOSE HYPOTHYROIDISM? Generally, the average temperature of an adult with a healthy thyroid and a healthy metabolism is 98.6 degrees Fahrenheit or 37.0 degrees Celsius, and that occurs around mid-afternoon or 3 pm. So if you take your mid-afternoon temp and find it in low 98′s or even in the 97′s, you have been given a strong clue that you may be hypothyroid. And a few report their mid-afternoon temp being in the 96′s. BRRRR.
Another temperature clue occurs first thing in the morning before you raise from your bed. Dr. Broda Barnes, a doctor who paid attention to clinical presentation and prescribed the pre-reformulated Armour, found that a healthy before-rising morning basal temp should be between 97.8 – 98.2. If it’s higher, you may be hyperthyroid, and if it’s lower, you are most likely hypothyroid. He also recommended under-the-arm temperature testing, but patients have found oral to be just as effective."
You'll need the 24 hr. Iodine Loading and Bromine tests.
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