A Simple At-home Thyroid Test
While this test certainly isn’t an official diagnosis of a thyroid disorder, it can give you some indication, so you can follow up with your doctor and advocate for further testing.
You will need a special BBT thermometer. You may already have one if you are charting your cycles.
As soon as you wake up in the morning, before you get out of bed or move around, put the thermometer between your arm and your armpit, next to the skin, and leave it for ten minutes. Record the readings for at least 5 consecutive days but 10 days is optimal. You should not test during the first 5 days of your menstrual period.
If the average BBT is below 97.4 Fahrenheit, you may have an issue with your thyroid. An average BBT between 97.8 and 98.2 is considered normal. Some practitioners say that temperatures from 97.6 to 98.0 are considered evidence of possible hypothyroidism.
The test should be part of an overall approach, and not the sole diagnostic. Holistic thyroid expert Dr. Richard Shames has said:
“For those who have already been diagnosed with hypothyroidism, the basal temperature test is an additional piece of observational measurement that helps determine whether a person is on the right medicine and/or the right dose, along with considering the response to medication, physical signs (especially ankle reflexes and skin temperature), and blood test results…Temperature testing, however, is not infallible, and — like any other test — should never be used alone to rule in or rule out a thyroid condition, or to dictate therapy. This is simply a good piece of information that should be used wisely.”
The BBT is a great tool to help diagnose an under active thyroid. However, there are a few caveats not listed in this post in order for it to work.
1. The temperature should be taken in the mouth or rectally for accuracy. Orally works fine, but you have to make sure the tip of the thermometer is placed all the way under your tongue, along the side of your last molar. It’s a bit uncomfortable, but the temperature varies slightly in different parts of your mouth. This is the best place. The digital thermometers only take 60 seconds to read.
2. Make sure your mouth is closed, and doesn’t open or it can affect the temperature.
3. Take your temperature at the same time every day. If it varies by an hour, then that can give you a false reading. Typically, the basal temperature raises 0.2 degrees every hour. So if you usually take your temperature at 7AM, but on the weekend take it at 8AM, you’ll see a slightly higher temp than normal. This can make a difference if you’re having borderline temps to begin with.
4. Because of the changes in the cycle, a woman’s temperature also changes in relationship to the hormones. Before the ovaries are active, the temperatures will be all over the place (around the time of your period). When they start getting active, the temperatures seem to level out. This is the time you also start to notice cervical mucus production. This is the crucial time to check for thyroid–the week before ovulation. The temperatures should be 97.3 or higher. If they’re lower, this is a great indication of an under active thyroid. After ovulation, the temperature should rise 0.4 degrees. If this shift doesn’t occur, this points to low progesterone! Another major symptom of PCOS…
My naturopath had me do this test, because I have practically every low thyroid symptom there is. I have had these symptoms for years, and have been tested numerous times by my doctors, but they always say the results are “normal.”
I always have a low body temp, taking my temp orally, it used to be around the 97 range, but now it’s even been dipping as low as 95. 5. I did the BBT under armpit as well for two weeks and got low temp every single time. I took this to my doctor, and she ran the test again at my insistence and then proceeded to tell me that a temp of 95.5 is normal. I am so frustrated, because I feel like there has to be something going on with my thyroid, even though it’s in normal range, and nobody will listen to me. Is anyone else experiencing this?