Reverse T3 is manufactured from thyroxine (T4), and its role is to block the action of T3. In past posts I’ve discussed how stress affects the adrenal glands, as when someone deals with any type of stress the adrenal glands will produce cortisol. But when someone is dealing with chronic stress on a frequent basis, then the adrenals will initially produce an excess amount of cortisol. The cortisol in turn will inhibit the conversion of T4 to T3. So you definitely don’t want the Reverse T3 to be too high.
Because it blocks the conversion of T4 to T3, a high Reverse T3 is more common in people with hypothyroidism and Hashimoto’s Thyroiditis, although every now and then I do see these levels high in some people with hyperthyroidism and Graves’ Disease. In either condition it is of course common for the patient to deal with chronic stress on a frequent basis, which in turn can cause inhibition of the conversion of T4 to T3 and lead to an increase in RT3.
How Can One Detect This Problem?
Not all doctors will recommend the Reverse T3 test when ordering your labs, and so you might need to look at other values. For example, if your free T4 is within normal range and the free T3 is low, then this can be an indicator of a high RT3. But of course the best method is to actually order the RT3 blood test. Sometimes the Reverse T3 won’t be high, but instead there will be a problem with the ratio between RT3 and the free T3.
The Medical Solution For High RT3 Levels
For someone who has abnormal RT3 levels, the medical solution will simply be to address the thyroid condition. So for example, if one has hypothyroidism, then the medical doctor will usually just prescribe synthetic thyroid hormone. If a person with hyperthyroidism or Graves’ Disease happens to have a high RT3, then the medical protocol will remain the same, which means giving the person antithyroid medication or recommending radioactive iodine.
For those medical doctors who do pay attention to the Reverse T3, they will usually either decrease the dosage of T4, and/or recommend for the patient to take T3. Cytomel is a popular brand which is given, and this can sometimes help to manage the symptoms of someone with a high Reverse T3 and/or an abnormal ratio between RT3 and free T3.
Correcting The Underlying Cause
Of course just giving someone Cytomel won’t cure the cause of the problem, which is why one needs to address the actual cause. If compromised adrenals are the problem, then one needs to address the adrenal gland issue. Obviously one first needs to determine whether someone has problems with their adrenal glands, which is where the Adrenal Stress Index test comes into play. I have discussed this test in other articles and posts, so I won’t get into detail here about adrenal testing. But I will remind you that it’s important not to rely on the blood tests with regards to the cortisol levels, not only because they measure the bound form of the hormone, but also because a single sample isn’t sufficient when determining the health of the adrenal glands.
Anyway, compromised adrenal glands isn’t the only factor which can lead to problems with the Reverse T3. If you read the book “Stop The Thyroid Madness” (or visit their website at www.StopTheThyroidMadness.com), you’ll notice that one of the things that is discussed is how low iron levels can lead to problems with the RT3 levels. As a result, in addition to looking at the adrenal glands, one needs to look at the iron levels. I think this is a good idea regardless of whether someone has a high Reverse T3, as many people with thyroid conditions have problems with their adrenals and/or have an iron deficiency.
Kent Holtorf wrote an article which discussed how chronic dieting can lead to an increase in the RT3 levels, and chronic illnesses such as diabetes, chronic fatigue syndrome, and fibromyalgia can lead to high levels as well. If this is the case then it shouldn’t be a surprise that conditions such as Hashimoto’s Thyroiditis and Graves’ Disease can also lead to this problem. With regards to dieting, the Reverse T3 has the opposite effect of free T3, which is to slow down the metabolism, as it does this in order to help gain weight.
In summary, many people with a thyroid or autoimmune thyroid condition should get their RT3 levels checked. This is especially true with someone who has hypothyroidism and Hashimoto’s Thyroiditis, but is also a good idea for some people with a hyperthyroid condition. I always talk about how blood tests don’t tell the entire story, which is true, but the reverse T3 can provide a doctor with some valuable information and at times can be vital to a patient’s recovery.