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Not understanding the thyroid test results

I thought initially that I understood the individual thyroid tests. I am about to go through additional testing next week. The initial results are:
T3 - Reverse                                36 (H)            Ref - (11-32)

Thyroid Peroxidase Antibodies      <10                       <35

T4 Free                                        1.4                        0.8 - 1.8

TSH, 3rd generation                       0.89                      .40-4.50

T3, Free                                        362                       230-420

Please explain how these work together to determine if test results are normal, hypothyroid, hyperthyroid.  Now, I feel totally lost with understanding my test results.                                  
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649848 tn?1534633700
COMMUNITY LEADER
I'm not real familiar with the rT3 issue, but here's what Wikepedia says about it.

"rT3, unlike T3, does not stimulate thyroid hormone receptors. However, rT3 nonetheless binds to these receptors, thereby blocking the action of T3. Under stress conditions, the adrenal glands produce excess amounts of cortisol. Cortisol inhibits the conversion of T4 to T3, thus shunting T4 conversion from T3 towards rT3. Consequently, there is a widespread shutdown in T3 binding across the body. This condition is termed Reverse T3 Dominance. It results in reduced body temperature, which slows the action of many enzymes, leading to a clinical syndrome, Multiple Enzyme Dysfunction, which produces the effects seen in hypothyroidism. Effects include fatigue, headache, migraine, PMS, irritability, fluid retention, anxiety and panic."

All of your blood test results are in the normal range; and according to your Thyroid Peroxidase Antibodies (TPOab), you do not have Hashimoto's Thyroiditis.  Your TSH is good; your FT4 is in the upper 1/3 of it's range, as is your FT3.  

If you were hypothyroid - most likely, your TSH would be either "high normal" or completely out of range (over the upper end of the range); your FT4 and FT3 would most likely be "low normal" or completely out of range (under the reference range).  It you were hypERthyroid, it would be just the opposite: Your TSH would most likely be very low and your FT4 and FT3 would be high.  

The way it works (or should work) is that the pituitary gland produces TSH (thyroid stimulating hormone) which tells the thyroid to produce more thyroid hormones.  When you have low/under active (or hypo) thyroid, your thyroid does not produce hormone in response to the pituitary gland.  In over active (hyper) thyroid, your thyroid produces too much  hormone.  

I guess looking at your results, I'd have to say "I only wish mine looked that good".  I hope this helps clarify your results a bit.  

Are you concerned about the weight issue?  That's a hard one to answer because everyone is different.  I've always been told that when my thyroid levels are "optimal", I will be able to lose weight and that's proving true for me.  There may be some little something that needs to be changed for you.  

You might want to look in on the Weight Loss and Dieting Forum -- there are quite a few ideas regarding weight loss there.  You might also want to start the food diary and exercise trackers here on MH -- they are great tools to help you stay on top of how much you are really eating and exercising, since it's really hard to keep track of that in your head -- calories in, fat, protein, carbs, calories out, etc -- is a lot to keep up with if you aren't recording it somewhere.
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Avatar universal
I'd like to add something here.

1. I have a goiter. I'll go through another thyroid scan and uptake in the future.

2. I am being treated for Reverse T3 with Liothyronine, 25 mcg per day

3. In the last 6 weeks, I have lost only 2 pounds. It fluctuates - going back up to the original weight.

4. I am officially in menopause taking prometrium 200 mg per day.  

5. Eating right -- and exercising 3-4 times per week.

I was born w/ a goiter, and it was partially removed when I was 2 days old. I was on thyroid meds for years. The doctor took me off when I was 17..... and ever since I've tested in the "normal" range. Recent test results indicated Reverse T3 for which I am taking the Liothyronine, 25 mcg per day. I am also taking thyroid Complex and D-3 1000 IU daily.
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