Expert Advice From Louise O’Connor, Australian Naturopath + Wellness Coach { About the book }

What Causes High Reverse T3 (RT3)? {There Are 5 Key Reasons}

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what causes high reverse T3If you are experiencing the typical signs and symptoms of an underactive thyroid but your TSH, free T4, and even your free T3 appear to be normal you may want to consider checking your reverse T3, which is an inactive form of T3.

This article answers the question ‘what causes high reverse T3’.

Firstly, what does a high reverse T3 mean to your health?

Too much reverse T3 can trigger a range of hypothyroid symptoms such as fatigue, depression, hair loss, muscle weakness, low blood pressure, and a slower than normal pulse rate.

The single reverse T3 test is included in the top 5 thyroid blood tests that are most useful to check your thyroid health. Many integrative doctors and Naturopaths now consider the reverse T3 blood test to be essential to effectively diagnose and manage hypothyroidism.

What causes high reverse T3 (RT3)? {There are 5 key reasons}

+ Unrelenting physical and emotional stress.

Ongoing stress and anxiety cause cortisol to soar. Cortisol is the hormone that helps you cope with stress.

There is a flip side to having excessive amounts of cortisol circulating in your blood stream. High cortisol inhibits normal thyroid hormone activity. This leads to an excess amount of reverse T3 being produced.

Health experts propose this is a protective response to slow metabolism and conserve energy during times of prolonged stress. Your body knows it simply cannot survive on high alert for too long. It can lead to burnout.

+ Extreme, or yo-yo dieting.

Cutting calories in an effort to lose weight sparks the body’s hard wired famine response. Your body feels the need to conserve energy when food becomes scarce and it achieves this by putting the brakes on your metabolic rate.

The easiest and quickest way your body can slow your metabolic rate and thereby conserve energy is by producing a massive amount of reverse T3.

+ Low iron is leaving you tired and breathless.

Chronic iron deficiency is a common finding in hypothyroidism. This deficiency needs to be addressed as a lack of iron impairs proper thyroid hormone metabolism. More specifically, low iron decreases healthy conversion of thyroxine (T4) to more active triiodothyronine (T3).

Adequate levels of iron are especially important to help fight fatigue as this mineral is required by your red blood cells to carry oxygen around your body. When iron is low your oxygenation levels are low and your body cannot utilise T3 at a cell level.

+ Long term exposure to toxins.

Toxins such as heavy metals, pesticides, and industrial chemicals switch on a physical stress response. Toxins also have serious effects on your thyroid health.

At a cellular level toxins can block the thyroid cell receptors so the thyroid hormones cannot perform their job, and toxins can enter the thyroid causing damage to the actual thyroid tissue. These factors sabotage day to day function of your thyroid. Over time the stress of dealing with toxins and the diminishing function of the thyroid can activate far greater production of reverse T3.

+ Systemic illness is a factor.

It is difficult to recover from reverse T3 dominance when a chronic underlying illness is not addressed. When your body feels under threat by a long standing illness it slows metabolism. Your body hits the ‘hibernation’ button to lessen the impact of a chronic illness.

For example, a latent viral infection may be causing widespread problems. This can lead to chronic fatigue syndrome which is often associated with over production of reverse T3.

If you have low T3 you should get your reverse T3 checked, especially if you have some type of long standing illness. On testing it’s typical to see low T3 and high reverse T3.

Treating excess reverse T3 secondary to a specific chronic illness is best discussed with a skilled healthcare practitioner.

Now I would love to hear from you. Did you find this article on what causes high reverse T3 (RT3) interesting? To leave your comment, feedback or questions about this thyroid health blog post just use the comment box at the bottom of this page.

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  1. Alanyo Alice Grace says:

    I want to acknowledge you for this critical but informative news.
    The symptoms described above seems to be what I am experiencing now. Since all my investigations (exceptT3 not done), were normal, I have all along been on Lugol’s iodine, 2=3 drops per meal without any significant improvement. Instead, the swelling of the (L) thyroid is increasing and those symptoms described are there. How can I be helped?
    Secondly, What are sources of metals described above? In other words, how do we get them into our bodies?
    Thanks a lot

  2. Louise O'Connor says:

    Hi Alice, it is vital to get all five thyroid tests done as this gives you an overall assessment of what is happening with your thyroid hormones. This means getting TSH, free T4, free T3, thyroid antibodies and reverse T3. When free T3 drops below 4.5 pmol/L and reverse T3 is high it is usual to experience hypothyroid symptoms. Unfortunatley heavy metals are pervasive in our food, water and air. For many people silver amalgam dental fillings are a source of mercury. This mercury leaches from the teeth over time and enters general circulation. Your thyroid requires more than iodine. If you are in Australia please take a look at ThyroSynergy. This is a thyroid health product that I developed. It has specially formulated with 10 ingredients to aid thyroid health.

  3. susan fletcher says:

    Hi would uou have a diet plan for low thyroid function im floundering a bit thankyou

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