Issue #257  November 24, 2014

Welcome to KnowYourThyroid.

Today, Louise O’Connor is going to explain the top 5 reasons your body produces too much reverse T3.




Your Thyroid: What causes high reverse T3 (RT3)?


If 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.

Reverse T3 is an inactive form of T3. High reverse T3 will trigger many of the symptoms of hypothyroidism.

Elevated reverse T3 may cause symptoms such as fatigue, depressed mood, hair loss, muscle weakness, low blood pressure, and a slower than normal pulse rate.

Many integrative doctors and Naturopaths now consider the reverse T3 blood test to be essential to effectively diagnose and manage an underactive thyroid.

The reverse T3 test is therefore included in the top 5 thyroid blood tests that are most useful to check your thyroid health.

You may be wondering what causes your body to produce high amounts of reverse T3. There are five key reasons…

What causes high reverse T3 (RT3)?

+ Unrelenting physical and emotional stress. Excessive stress and anxiety causes cortisol to soar. This is a normal response. Cortisol is your body’s major stress hormone and plays an important role in helping you cope with stress.

However there is a flip side to having huge 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 may be 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 to lessen the possible negative effects of the 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.


Louise O’Connor is the author of The Natural Thyroid Diet. The 4-Week Plan To Living Well, Living Vibrantly,  a breakthrough in holistic thyroid health management. This book was first written back in 2007. Since that time it has been revised numerous times with new information. The expert advice contained in The Natural Thyroid Diet. The 4-Week Plan To Living Well, Living Vibrantly has also literally helped thousands of people around the world., including all associated social media, is for informational purposes only and
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