Thyroid Self-Test

This post was updated on Oct.17, 2013

Many of my clients have not been diagnosed but suspect they’re hypothyroid based on symptoms lists, or they have been told that they’re fine and sent along their merry way when they know in their hearts that they’re hypothyroid. This is because the majority of doctors ONLY test for TSH (thyroid stimulating hormone (thyroid stimulating hooey)). People can have “normal” TSH yet their hypothyroidism rages on.

One way to test for potential hypothyroidism is to do a basal body temperature (BBT) test at home. According to Dr. John Douillard, “Before blood tests were available, the thyroid was evaluated by basal body temperature and the signs and symptoms presented by the patient. Today, these traditional tests have been replaced by modern blood tests. It has now become clear that these blood tests alone are not accurate enough.” 

This test should be used in conjunction with thyroid labwork.

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A basal thermometer is required for this test; a regular thermometer will not give you the same reading. You can purchase a basal thermometer at most any drugstore or online. Basal thermometers are ultra sensitive and can give you a more accurate temperature.

There is discrepancy in opinion about whether the basal thermometer should be digital vs. mercury. Some of the authorities I respect say that it should be glass/mercury because the digital thermometers stop reading after a minute or two and are not as accurate.

Generally, I’ve found the digital thermometers to work just fine. You don’t need 100% accuracy necessarily; you simply want to know if your temperatures average 97.8 degrees or less. If your average is borderline, or right around 97.8, I still suggest supporting thyroid function.


Keep a basal thermometer beside your bed. When you awaken in the morning, at roughly the same time and before moving around at all (even before you make a trip to the bathroom), tuck the thermometer snugly in your armpit and keep it in place for 15 minutes. Remain as still as possible. Remove the thermometer, take a reading, and write down the results.

Follow this procedure for three days, then determine an average reading by adding all three readings together and dividing by three. If your average temperature is below 97.8 degrees F, you most likely have an underactive thyroid.

It’s important to shake down a glass thermometer the night before because shaking just prior to the test will raise your temperature and throw off the reading. For women still cycling, BBT for thyroid function should be started on the second day of menstruation because mid-cycle, there is a natural rise in temperature with ovulation.


Unfortunately, all comments on this post written prior to Feb. 28, 2013 were inadvertently wiped out. Ouch.

I have many of the symptoms of Hashimoto Syndrome, however all my thyroid tests come back within the normal range. What do I do now? I am doing the thermometer test. This is day one and I was 96.5. I will do it for the next two days, but suspect they will be close to the same.

Hi Rebecka,

We have worked with countless clients in your same boat -- normal lab tests, but many symptoms of Hashimoto's and/or hypothyroidism. There are many reasons why lab values may appear normal, even when the thyroid may not be functionally properly (or optimally). If you want to take thyroid medication, you'll have to continue searching for an open-minded physician who will take your symptom seriously. Alternatively, many of the dietary and lifestyle strategies we suggest are beneficial to the thyroid and can help alleviate symptoms. If you are interested in working with us, please use the form on the Contact page to get in touch.


I took the home test. My basal temp for three days never hit 97.8. It was 96.5 for two days and 96.7 the third. I'm going to look at the dietary and life style strategies and talk to my doctor. She is quite receptive to trying new things. If that doesn't work, I'll be in touch. Thank you for your help.

Hi Rebecka,

It's great to hear you have an open-minded doctor that you feel you can work well with. Please don't hesitate to reach out if we can be of further guidance or support.


Hi, I'm confused in some ways. I was diagnose with Hashimoto Hypothyroidism a few years ago and I was on lexothyrine. However in February 2014, my doctor said my blood tests indicate that I was normal and that I don't have to take it any longer. However I am increasingly displaying symptoms as displayed above. I want to take kelp supplements (150gmc) per day as I was reading how it is beneficial for people with thyroid conditions. What would you advice?

Ely, I take "normal" with a grain of salt. Many doctors are using outdated (and very misleading) thyroid reference ranges. Although labwork is important, symptoms always trump labs. Iodine supplementation is the outdated recommendation (from the 50's and 60's) for those with hypothyroidism. If you have Hashi's, it can be detrimental. But small doses may be fine.

Hi Jill, 

thanks for the info. I decided to get a proper lab test with a second opinion from another doctor. Seeing this new doctor was refreshing. It was great to hear someone assuring me that it was not all in my head and that I do have a thyroid problem. I am currently on 100.gcm dose of thyroxine, went for a thyroidectomy on my right thyroid as there were large suspicious activity. Cut down significantly on gluten. Weight has dropped from 79kg to 71kg with more or less regular menses. 

Thanks for the info. You're right, doctors remained outdated and how dangerous it is for thyroid patients. 


I hav not been diagnosed with Hashimoto but have had for some time issues with thyroid which were treated with homeopathic remedy approx 10 years ago,Dr now thinks I have issues again and iam on a naural liquid iodine supplement that is used for animals and made from sea weed, most troubling is the prickling skin,and now aching glands???Im not that tired but do have dry eyes and mouth,are these symptoms of thyroid issues too? I did not see the prickling skin or itch in the list you provided?.Im nervous as I have has Upper right quadrant pain for months(this has settled though since i gave up dairy and gluten?)Hot and cold feelings and basal cell average of 35.8 I have been to Dr about 8 times in as many months and I feel like such a hypochondriac,any ideas please would be greatly appreciated :)

Hi Jen,

Thanks for your comment and we truly are sorry to hear about your symptoms. Because everyone is different, your collection of symptoms represent a complex condition and cannot be answered responsibly on a blog comment. We’d love to help you – if you’d like to speak with one of our coaches, you’re welcome to schedule an introductory session via our Contact page.



How would post-ovulation/possible conception affect the basal body reading for this test? I'm 7dpo, so don't have a + yet, but am wanting to look into my thyroid function.


Your temperature will stay elevated if you’ve conceived.

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