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 Barnes Basal Body Temperature Test

Despite the sensitivity of all the tests the doctors can give a patient today, a mildly hypothyroid or hyperthyroid person can still appear normal in a test. Many people have symptoms and are clearly affected, yet they complain that no doctors will help them. Even if their tests come up "normal", they suffer tremendously with symptoms of either of these conditions daily.


TSH tests and blood tests are useful to help diagnose thyroid problems but should not be used alone. Symptoms are the most important factor. It is rare that a blood chemistry panel shows your true condition because the values measured are only about 30% accurate. It is common for a person with thyroid problems to have a completely normal thyroid panel. This is why the Thyroid Panel is considered by many to be inadequate. It is common for a hypothyroid person to have a low TSH value, which is usually interpreted as hyperthyroidism, not the reverse, despite many symptoms of low thyroid (depression, dry skin, weight problems, chronic infections, female problems, hair loss, low blood sugar, and so on). TSH tests are not as scientifically accurate as they need to be.
There is a sophisticated test to reveal even mild low thyroid and it is the TRH (Thyrotropin Releasing Hormone) test. This test requires an injection, followed by one or more blood draws at 15, 30 and 45 minute intervals. This test is accurate, but is expensive and inconvenient for both patient and the lab.
There is one simple thing almost anyone can do at home to uncover a thyroid problem: Take your own temperature!
The "basal body temperature" test was developed by Broda O. Barnes, M.D. Because thyroid hormone is so vital to cellular metabolism, reduced thyroid function often manifests as deviation in body temperature away from the normal level of 98.6oF / 37oC.
Barnes recommended the following procedure:
Immediately upon awakening, and with as little movement as possible, place the thermometer under the tongue or in the rectum. Leave it there for 10 minutes. Record the readings on three consecutive days at exactly the same time of day.

Note : a modern digital thermometer can give a reading in less than a minute, but it is wise to check the accuracy with a clinical thermometer first, then if deemed accurate it is so much more convenient to use the digital thermometer

If the average temperature over the three days is less than 97.8oF / 36.6oC then, according to Barnes, one may have hypothyroidism.

Where the temperature is consistently above 98.6oF / 37oC this is an indication that one may have hyperthyroidism

The temperature can also be taken by means of placing the thermometer under the arm. In this case readings will generally be lower than oral/rectal readings, and for the purposes of this test a factor of 0.8oF or 0.5oC should be added to the reading when determining thyroid activity levels.

Even if you have had a blood test and were told your did not have a low/high thyroid reading, you might go back and look at the test results again. You may find that your blood levels of thyroid hormones are actually within the so-called "normal" range but below or above the midpoint. If so enormous benefit may be gained from thyroid supplementation.
Your optimum oral temperature should be 98oF / 36.7oC in the morning before arising. Your oral temperature should rise to 98.6oF / 37oC to 99oF / 37.2oC  for about 10 hours a day (starting between 8 am and 11 am).

Please note that this test will give a good indication of thyroid problems but is not definitive. Other factors can affect body temperature. Temperature may be disturbed by several factors such as taking readings at different times, alcohol, illness, a restless night, stress etc. If the readings have a base rate in a menstruating woman of 97.2oF / 36.2oC or less, or a constant reading below this in other women, men and children, an underactive thyroid is very likely. An overactive thyroid would be likely in cases where the temperature is consistently above 98.6oF / 37oC. (note: in  menstruating women, on day 1 of the cycle on the first day of menstruation, the temperature will be at a lower level, during ovulation the temperature rises and remains at this higher level until dropping just before the next period. This normal cycle will be affected by an underactive, or overactive thyroid and can be used as an effective alternative to blood tests).
A good test time is to take your oral temperature between 11 am and 3 pm. The next time to do this is 20 minutes after lunch which is when your thyroid function should be at its best.
It is important to work on getting and keeping your temperature at 98.6F / 37oC The thyroid system is a vicious circle, one thing leads to another until bacteria, parasites, and viruses attack and cause other diseases and symptoms, including the body's wanting to attack itself. When body enzymes are not at the correct temperature, they don't convert into the correct hormones, which then cause illness. Even if your temperature is normal and you still have symptoms, you may have a low grade infection that is raising your temperature. Symptoms are a really important factor that need to be taken into account. Once the low grade infection is taken care of, you will be able to do the test again and pick up a low temperature.

An Additional Indicator

Pulse Rate as Diagnostic of Hypoactive or Hyperactive Thyroid: Resting pulse taken when you have been sitting or lying down for at least should 5 minutes. If consistently less than 85 beats per minute, suggests, especially if temperature is consistently subnormal, a hypoactive thyroid. (Women must measure temperatures during menses or when they are not ovulating). Pulse rates higher than 85 at rest on a consistent basis may indicate hyperthyroid, but not always and can be the result of infection, food intolerance and excess adrenalin.

Further Reading on Thyroid Problems


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