(adapted from Dr.Aviva Romm, MD, 2014)
I see a lot of patients that complain of weight gain, fatigue, constipation, dry skin, PMS, and complaining of always being cold. All these symptoms point to the possibility of hypothyroidism, or under active thyroid function. Sometimes, their TSH (thyroid stimulating hormone), the most common test for thyroid function, has been tested and may still fall into the “normal range”. However, TSH is only one of the markers for abnormal thyroid function, and many patients are unaware that there are other tests that can give a much better picture of thyroid health and function.
Statistically, hypothyroid is an under diagnosed condition. In fact, in the US only ½ of Americans that have hypothyroidism know it.
What is the Thyroid?
The thyroid is a butterfly-shaped gland that sits at front of your neck and controls your metabolism. It therefore controls your weight, energy levels and also plays a role in cholesterol and hormone production.
When the thyroid is out of balance and not functioning optimally you can gain weight, have sluggish bowels, experience dry skin, have fertility problems, brain fog and feel tired…even if you have a great diet and activity level!
The Key Thyroid Tests
Thyroid tests should be easy to obtain from your primary doctor, naturopathic doctor or functional medicine doc. However thyroid tests do take some skill to interpret and some docs may be reluctant to order more than a TSH test. If this is the case, consider getting a second option by a doctor that is familiar with thyroid health and testing.
Thyroid Test #1: TSH (Thyroid Stimulating Hormone)
TSH is the commonly order thyroid test. This hormone is produced by the pituitary gland (a small gland in your brain). TSH communicates with the thyroid to tell it to produce more thyroid hormones T3 and T4. When all is going well in the body, TSH is in a normal healthy range and so is T3 and T4. When T3 and T4 (those important thyroid hormones produced by the thyroid gland) are LOW, TSH starts to INCREASE, telling the thyroid gland to produce more T4 and T4.
The “healthy TSH range” has become a somewhat controversial topic in medicine. Most Canadian labs consider the upper range of TSH to be 4-5mU/L. However, many experts, including many conventional endocrinologists, consider the upper limit of TSH should be no higher than 2.5-3mU/L. This is based on the data collected on Americans without any hypothyroid symptoms. When they have a TSH test done, this is the common upper range.
Thyroid Tests #2 and #3: T3 (Triiodothyronine) and T4 (thyroxine)
As mentioned above, T3 and T3 are hormones produced by your thyroid gland. T4 is produced in much higher amounts by your thyroid gland, and then is converted into T3 in the periphery. This is important because T3 is the more active form of thyroid hormones and is necessary for proper metabolic function.
Thyroid Tests #4 and #5: TPO and TGAb (Thyroid Antibodies)
As mentioned previously, autoimmune hypothyroidism is the most common cause of hypothyroid. As with any other health condidition, to achieve optimal health we must look at the underlying cause of the problem. If a patient has hypothyroidism, but does not address the autoimmunity (if present), the problem will not be addressed at the root cause. Thyroid antibodies can also be measured every 6-12 months to gauge how thyroid treatment is progressing.
Thyroid Test #6: Reverse T3 (RT3)
Although there is some controversy over the usefulness of this test, I have personally found it of benefit in my practice, especially if hypothyroid symptoms are persisting despite treatment. Sometimes, when the T4 is being converted to T3, it can be converted into RT3, a less active form of T3 that the body cannot use as well as T3. This can happen is one is under a large amount of stress or is sick. If the patient it producing a large amount of RT3, certain medication or supplements can help replenish the body with T3 and encourage the body to produce T3 over RT3.
If you have an inkling that your thyroid health is sub-optimal and your doc is not open or familiar with thyroid testing, consider switching docs or having a second opinion.
Yours in Health,