To properly treat hypothyroidism, you must first know your Ts. Thyroxine, or T4, is the thyroid "storage hormone." Triodothyronine, or T3, is the "energy hormone." For the body to use T4, it must first convert it to the active hormone T3, giving energy to every cell in the body.
Another critical thyroid hormone is reverse T3 (RT3). Reverse T3 is the body's "emergency brake." Many endocrinologists believe that Reverse T3 is simply an inactive metabolite with no physiologic effect on the body. They couldn't be more wrong.
Reverse T3 is more powerful than the medication most commonly used to decrease thyroid function in hyperthyroid patients. In some patients, instead of properly converting T4 to T3, the body converts too much T4 to reverse T3, effectively shutting down the body. These patients often experience debilitating fatigue, and continue to get worse in spite of taking T4 thyroid hormone medication.
What Causes Too Much RT3?
Thyroid hormone conversion problems can be caused by a number of common issues, including significant stress, depression, a history of dieting, insulin resistance, obesity, diabetes, chronic fatigue syndrome, fibromyalgia, autoimmune diseases, chronic inflammation, chronic infections, PMS, iron deficiency, and many more. Any one of these issues could cause a patient to have too much RT3 or an improper T3/RT3 ratio.
Reverse T3 Issues Must be Addressed
Now imagine that a patient with a thyroid hormone conversion problem (i.e., too much RT3) is seeing a doctor who "doesn't believe in RT3." It's a recipe for disaster. The more T4 the doctor gives the patient to improve hypothyroid symptoms, the worse the patient will feel, because too much of that T4 is being converted into more RT3. And all the while, the patient's TSH test appears to be "normal." Although the patient isn't getting better, the doctor refuses to order lab tests to check for RT3, and tells the patient that she's fine, that her labs are in range, that she must be depressed, or that it's all in her head.
Too Dangerous to Ignore
The problem is that while some doctors don't believe in RT3, more and more patients are getting sicker. Regardless of whether or not your TSH is "in range," if you have too much RT3, you are hypothyroid. Not treating thyroid issues can have serious consequences, including mental health issues, difficulty breathing, congestive heart failure, stroke, Alzheimer's disease, and more. At its most dangerous level, untreated hypothyroidism could eventually slow the body to the point where you would fall into a coma.
Treating Thyroid Conversion Issues
Treating a patient with RT3 issues requires a deep understanding of the subtle nuances and complexities of thyroid disorders, as well as a willingness to treat based on a combination of factors, including patient symptoms, rather than simply relying on standard thyroid tests like TSH and T4. It is critical to do comprehensive testing, including a full thyroid panel for TSH, free T4, free T3, RT3 and thyroid antibodies. In addition, a sex hormone binding globulin (SHBG) test can help determine the cellular level of T3. A goal of proper thyroid replacement is to have an optimal metabolism, so this should be checked before and during treatment. Reflex response tests should also be done, because studies show that the speed of the relaxation phase of a reflex is a better test for hypothyroidism than the TSH. Thorough testing and examination to determine what is causing the conversion issues are key, and steps should be taken to correct any related problems.
It's also important to look beyond the standard T4 treatment. Patients with RT3 issues often see improvement with preparations containing combinations of T4 and T3, and especially with straight time-released T3. By providing the body with some or all of the T3 that it needs, the thyroid will produce less T4. With less T4 to convert to RT3, the patient's system can slowly regain proper thyroid hormone balance. Conversely, continuing to give T4 preparations or refusing to treat RT3 issues means the patient will become increasingly hypothyroid.
Patient Involvement is Key
Treatment with T3 requires careful monitoring and a partnership between the doctor and patient. While the right levels of T3 replacement can help a patient reduce RT3 levels and feel better, too much T3 can bring a patient into a hyperactive state. It is important that patients on T3 monitor their body's response to the T3 by checking their pulse and heart rate when increasing their dosage, and also watch for hyperthyroid symptoms such as anxiety, increased sweating, and weight loss. Too little T3 is not good, but neither is too much. A simple adjustment in medication levels can bring these patients back to the right balance, so it's important to stay in touch with your doctor and let him know how you're feeling.
Don't Believe the Numbers
It's also important to know that treatment with T3 causes specific changes in lab tests that can cause concern in doctors who are not trained in this treatment protocol. Because this treatment provides the active thyroid hormone T3 that your body needs, the pituitary gland produces less TSH, and the thyroid produces less T4. At the same time, levels of T3 raise in the body. To the untrained eye, a patient can appear dangerously hyperthyroid. But to the physician who understands this protocol, these changes in lab levels are expected, and treatment is monitored based on a combination of the patient's laboratory tests, symptoms, metabolism and reflex speed rather than just a lab number.
Don't let the numbers fool you. If your labs say your thyroid levels are fine but you feel increasingly severe hypothyroid symptoms, it's important to get checked for Reverse T3 issues. Your life might depend on it.