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Thyroid Test results help please

I had thyroid tests done and got my results back. Any help understanding the results would be greatly appreciated.
Free Triiodothyronine (fT3): 2.8 pg/mL   Normal Range   2.1 - 4.2 pg/mL

Free Thyroxine (fT4):  1.5 ng/dL   1.5 ng/dL   Normal Range   0.8 - 2 ng/dL

Thyroid Peroxidase (TPO):   18 IU/mL   Normal Range   0 - 60 IU/mL

Thyroid-stimulating Hormone (TSH):  1.6 uU/mL   Normal Range   0.5 - 4.7 uU/mL

I don't know what these results mean.

The symptoms that I have are:
-some days I am really fatigued even though I exercise regularly
-low sex drive
-thinning hair and eyebrows
-can't lose weight even though I exercise regularly, eat mostly well and drink tons of water
-when my feet get cold, my toes go numb and turn white until I get them warm again
-brain fog

Any advise or feedback I can get would be greatly appreciated!

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649848 tn?1534633700
Since you're not taking any thyroid hormone medication, it would appear that you probably need some...

So now to explain what the tests mean... if I tell you things you already know, it's just because I don't know how much thyroid information you actually have, so I'm going to basics.  

The thyroid produces 2 major hormones - those are T4 and T3.  It produces much more T4 than it does T3.   Of the total T4 produced, most is bound by protein so it can't be used.  The unbound portion is called the "Free T4" (free meaning unbound and available for use).  Free T4 isn't used directly by the body/individual cells.  Free T4 converts to, either Free T3 or Reverse T3 (rT3).

Like T4, most of the T3 in your body is bound by a protein and can't be used.  The unbound portion is the Free T3 and is the hormone that's used by nearly every cell in your body.   rT3 is inert (does nothing), but it can block Free T3 receptors.  Some reverse T3 is good/natural, but if more Free T4 is being converted to rT3 than Free T3, we tend to have hypo symptoms (like yours)

Most of us do best when Free T4 is at/about mid range. Yours is good at 58% of its range.  In addition, most of us need Free T3 to be in the upper half to upper third of its range.  This is where you seem to be having issues because your Free T3 is only at 33% of its range.  

TSH is Thyroid Stimulating Hormone, a pituitary hormone that stimulates the thyroid in an effort to get it to produce more hormones.  Typically, with a Free T3 as low as yours, plus the symptoms you have, we'd expect to see TSH much higher than yours.  

Thyroid Peroxidase is an enzyme used to produce thyroid hormones... The test you had done, should actually be labeled "Thyroid Peroxidase Antibodies" (TPOab).  Antibodies are produced when we have an autoimmune condition called Hashimoto's.  The antibodies attack and eventually, destroy the thyroid so it no longer produces hormones (T4 and T3).  Your antibody count is lower than the reference range, indicating that you may not have Hashimoto's.  However, there is another antibody test that should be done that's also an indicator of Hashimoto's.  That's Thyroglobulin Antibodies (TgAb).  When we have Hashimoto's, we will eventually become hypothyroid because our thyroid can't produce the hormones we need.  

These hormones control metabolism, body temperature, heart rate and many other body processes.  

Typically,  with hypothyroidism TSH is higher than normal because the pituitary (called the Master Gland) is calling for more hormones, but the thyroid doesn't respond, so the pituitary keeps producing TSH in an effort to get the thyroid to respond.  Sometimes, however, something happens to the pituitary or hypothalamus (another gland in the brain) and it doesn't put out enough TSH to stimulate the thyroid... In these cases, there's nothing really wrong with the thyroid, it's the pituitary that's malfunctioning.  This is called Central (or Secondary) hypothyroidism.  Many doctors will misdiagnose someone with Central/Secondary hypothyroidism because the TSH is low and often, that's all they look at, even if they order Free T4 and Free T3 along with it.  

In addition, some people have problems converting Free T4 to the usable Free T3.  Since your Free T4 is more than adequate, but your Free T3 is quite low, I'd think you either have Secondary hypothyroidism or a conversion issue (Free T4 not converting to Free T3 or converting to too much rT3).  

My suggestion would be to request the other antibody test (TgAb) to help rule out Hashimoto's and ask for Reverse T3 (along with another Free T4 and  Free T3 since they need to be done at the same time), which is a hormone that mimics Free T3 - it's a mirror image.  

Also, if you've been tested for Vitamin B-12, Vitamin D and ferritin, please post results with reference ranges.  Many of us with hypothyroidism are deficient in all 3.  Vitamin B-12 and D are necessary for the metabolism of thyroid hormones.  Ferritin is the iron storage hormone, which tells how much iron we have in store.  Iron is necessary for the conversion of Free T4 to Free T3.  If you haven't been tested for these vitamins/mineral, please ask your doctor to order them.  

I'd also suggest that you ask for a thyroid ultrasound to determine whether or not you have nodules on your thyroid.  Many of us do and most of the time they're no problem, but if they exist, they should be monitored.

I hope this helps and if I confused you, please feel free to ask for clarification.  :-)

Helpful - 0
Oh my gosh, thank you for the very informative response to my question.  Your detailed response is very helpful; you explained a ton of info really well and made it easier to understand. Thank you soo much!

I don't have health insurance so I don't usually see a doctor unless I get really sick. I actually ordered the thyroid test online and these were the results. I guess now with this knowledge, I need to make an appointment and see what's actually going on.

Again, thank you so much for the information you provided. I searched all over the internet, but I couldn't make any sense of it anything, so you really helped a lot!
I'm happy to know my information was useful.  

Since you don't have insurance, I might suggest that you go ahead and get the other antibody test, I mentioned as well as the rT3 and if you can afford it, the vitamin/mineral tests I mentioned as well.  If you order the Ferritin, look into a complete iron panel since Ferritin is a storage hormone for iron.  If you have low ferritin, you'll need an iron panel anyway to find out exactly what your iron is.

I don't know where you ordered your tests from, but there are numerous places from which to order them, so there may be somewhere less expensive.  Just a thought.  

By doing the further tests, when you do see a doctor, you will have more information and be able to point at the problem a lot easier or if it's a conversion issue, you may be able to resolve it on your own, by supplementing or changing your  diet.   Don't be surprised if a doctor tells you there's nothing wrong because your TSH is "in range" since many doctors only look at TSH and if it's good they think all is well.

When you get the rT3, you really need to get another Free T4 and Free T3, since the raw rT3 result isn't as important as the ratio between FT3/rT3 and the results need to come from the same blood draw in order to be accurate.  

By the way - you did an excellent job picking the tests, without knowing a lot about thyroid.  :-)

If there's anything further I can help you with, please don't hesitate to ask.  
649848 tn?1534633700
Hmmm - I responded to this a couple of hours ago, but I guess my comments didn't post for some reason.  

Have you been diagnosed with a thyroid condition?  If so, what condition were you diagnosed with?  Also, are you currently, taking any type of replacement thyroid hormone medication?  If so, what medication/dosage are you taking?
Helpful - 0
Hi, I have not been diagnosed with a thyroid condition nor am I taking any type of replacement thyroid hormone medication. I just had the test done last week and got my results back today and I have no idea what the results mean.
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