Can Basal Body Temperature Diagnose a Thyroid Condition?

There have been articles which say that Basal Body Temperature (target range being 97.8 to 98.2 ) is much more accurate than blood tests.

A woman doctor has used her Basal Body temperature (BBT) as a guide to determine if she has met her optimum thyroid medication level. She took her temperature under her arm first thing upon waking for 3 days in a row and writes it down. Her basal temperature for the 3 days ranged from 95.8 to 96.8, though her Thyroid-Stimulating Hormone or TSH level at her last doctor was in the normal range. Since that TSH test her thyroid medications have been increased by her new doctor, and her BBT is still low.

Basal Body Temperature Should Be Part of the Equation

Dr. Richard Shames, a medical practitioner for 30 years and an expert on thyroid related topics, says that there is considerable evidence that current tests both for the diagnosis of hypothyroidism and for the management of a case under treatment are tests that lack sensitivity and accuracy. Faced with this situation, in my medical practice and in my second opinion telephone coaching sessions with patients of other practitioners, I absolutely insist on basal temperatures being part of the equation".

Apart from being a diagnostic maneuver that Dr. Shames uses, BBT is also an important additional data along with symptoms, family history, related conditions, and signs of abnormality upon physical examination. For people who have been diagnosed already with hypothyroidism, BBT test is an added observational measurement that helps in determining whether a person is on the right medication and/or the right dose. This includes considering responses to medication, physical signs (e.g. ankle reflexes and skin temperature), and blood test results.

However, Shames also says that basal temperature testing is "much more accurate than the blood tests" should be taken with a grain of salt. What this boils down to is that medical practitioners and patients should be prudent enough and use as many different sources of information as possible. This helps in the difficult decision of whether to or not to treat a health problem as a low thyroid issue or , if already being treated, whether or not to add or change medication or supplements.

Dr. Shames shares this example:

"I generally find out on a first conversation with a potential thyroid sufferer what is the percent of total optimal function that they currently enjoy. Some people say to me, "Dr. Shames, I’m glad I can talk to you on the phone from across the country because I’m only feeling 20% of my prior self, but my doctor says my TSH test is normal, so they are not going to do anything further."

This is a person who should be following their basal temperature, rather than their TSH. Most likely their basal temperature will still be low, suggesting a need for further medicine, and I endorse people going along with that suggestion regardless of TSH levels."