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T3/T4 Free Optimal levels?
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T3/T4 Free Optimal levels?

Hi!  I know I've seen them listed on here somewhere before, but can't find them.  What are the optimal levels for T3/T4 labs.  The range used locally is:

T4 Free 0.9-1.8
T3 Free 2.3-4.2

I've been on Thyroid NP, which I love, for a little over 2 1/2 months now, but still feel something is a bit off because i have a little lingering dizziness from time to time and I'm going to ask my Endo to run these tests.  Just wanted to get some expertise here...lol...THANKS!
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Avatar_m_tn
I like what you say about your doctor.  That will be a big help. Your doctor is right that Free T3 will show a bit higher than Free T4 when taking NDT type thyroid meds; however, the actual level also depends on the daily dosage, and the amount of natural thyroid hormone your thyroid gland is producing as well.  So to get a better picture of your status, you should absolutely test for Free T3 and Free T4, along with Reverse T3, Vitamin D, B12, and ferritin.  It is important to know all of those.    

One more thing.  Was the cause for your hypothyroidism identified?  The reason I ask is that the most common cause for diagnosed hypothyroidism is Hashimoto's Thyroiditis.  With Hashi's the autoimmune system erroneously identifies the thyroid gland as foreign, and produces antibodies that attack the gland.  Over an extended period the gland is destroyed, requiring increasing doses of thyroid med to offset the loss of natural thyroid production.  If Hashi's is involved, that might explain a return of hypo symptoms.  The tests for Hashi's are TPO ab and TG ab.
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Avatar_m_tn
There is no exact levels that fit everyone, as a rule of thumb Hashimoto's sufferers feel best when the Free T4 is at 50% of the range and Free T3 at or about 66% in its range. There is a little math used to figure percentage of range, if you want to post your levels and the ranges provided for each Free T3 and Free T4, I can figure the percentage for you and see where you stand.   Best Regards FTB4
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Avatar_m_tn
The optimal levels are those that eliminate your hypo symptoms.  Everyone is different, but many members, myself included, say that symptom relief for them required Free T3 to be in the upper third of its range, and Free T4 around the middle of its range.  Free T3 is the most important because it largely regulates metabolism and many other body functions.  Scientific studies have shown that Free T3 correlated best with hypo symptoms, while Free T4 and TSH did not correlate at all.  

A good thyroid doctor will treat a hypo patient clinically by testing and adjusting Free T3 and Free T4 as necessary to relieve symptoms, without being constrained by resultant TSH levels.  You can get some good insight into clinical treatment from this letter written by a good thyroid doctor for patients that he sometimes consults with after initial tests and evaluation.  The letter is then sent to the participating doctor of the patient to help guide treatment.  In the letter, please note the statement, "the ultimate
criterion for dose adjustment must always be the clinical response of the patient."

http://hormonerestoration.com/files/ThyroidPMD.pdf

The dizziness you mention can be related to being somewhat hypo still.  Do you have any other lingering hypo symptoms?  

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1797743_tn?1389217285
Thanks to both of you.  I have an Endo who has me on Thyroid NP and that was a big deal when i was doctor shopping.  He was one of the few who openly prescribes it.  I wanted to get away from the Synthetics.  Now I find myself trying to make the adjustment.  He said he will gladly test my t3 free and t4 free, but that when a patient is on Armour or Thyroid NP the T3 tends to run a little high and the T4 tends to run a little low.  I'm on the lowest dosage and have been taking it since Nov 8th.  I have to admit most of my symptoms have completely disappeared, but I have a cold now and have had a few down days and a dizziness that comes and goes.  I like that this Endo stated to me that he doesn't treat solely on lab results because if I'm still having symptoms something is off.  I've never had a doctor come out and say that before even though I've read that it's the way it should be.  I'm hoping that when this cold has passed I will feel a lot better, but it just stinks right now.  At the same time, I'm glad I have finally found a doctor who is willing to work with me and not be so rigid.  I sincerely appreciate the info you two have given me.  Gimel, in response to your question if I have any other lingering hypo symptoms, no, or I should say I didn't until I got sick earlier this week.  I've got the sinus crud going on right now.  Up until then I was pretty much symptom free.  Right now I'm dealing with the dizziness, I've been a little more tired then usual, but I'm taking an antihistamine and I've had a few aches and pains (stiff neck and upper shoulder area).  It scared me because this is what I felt at the beginning of my diagnosis.  I'm hoping it's all related to the crud and forcing myself to sit still at my desk all day working.
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1797743_tn?1389217285
one last question....is it normal to have dizziness come for short periods of time and disappear for weeks at a time and then return for a few days?  I haven't noticed any correlation to the timing of the dizziness.  The only other meds I take are 25 mg of Cozaar for HTN and 2000IU/day for Vitamin D Def.  When I first started the Thyroid NP, I had more energy then ever and the dizziness disappeared for well over a month, but then the manufacture changed and the dizziness reappeared.  I went to the pharmacist and requested to stay with the same (original)manufacturer and have been back on that for 3 weeks now.  I'm hoping it's just me readjusting to the original med again.  I'm so confused at this point and seriously tired of trying to figure it out.  Just having one of those blah days! :(  Thanks for any info you can give
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Avatar_m_tn
I like what you say about your doctor.  That will be a big help. Your doctor is right that Free T3 will show a bit higher than Free T4 when taking NDT type thyroid meds; however, the actual level also depends on the daily dosage, and the amount of natural thyroid hormone your thyroid gland is producing as well.  So to get a better picture of your status, you should absolutely test for Free T3 and Free T4, along with Reverse T3, Vitamin D, B12, and ferritin.  It is important to know all of those.    

One more thing.  Was the cause for your hypothyroidism identified?  The reason I ask is that the most common cause for diagnosed hypothyroidism is Hashimoto's Thyroiditis.  With Hashi's the autoimmune system erroneously identifies the thyroid gland as foreign, and produces antibodies that attack the gland.  Over an extended period the gland is destroyed, requiring increasing doses of thyroid med to offset the loss of natural thyroid production.  If Hashi's is involved, that might explain a return of hypo symptoms.  The tests for Hashi's are TPO ab and TG ab.
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1797743_tn?1389217285
Thank you Gimel.  No, the cause of my hypothryoidism was never identified.  It was diagnosed in the ER after my final dose of prescription Vitman D was taken...about 3 days after.  I'd been diagnosed with Vitamin D Def by my Primary Care Doc after days of dehydration/dizziness.  My TSH and T3, I believe were tested at that time and normal.  Fast forward to 12 weeks later and I had palpitations, etc. I didn't feel like I was getting the info I needed from my PCP so I found an Endo who lived close by and was convient.  She tested my cortisol and Anti TPO...all was normal.  She also took me off of my levothyroxine at the time...1/2 of the smallest dose every day because she said that she rarely treated anybody who had a TSH below 10, mine was 4.8 when diagnosed.  Well, that just set my body in all kinds of different directions FAST.  I started retaking my levo and contacted a new Endo who is about 30 miles from where I live, who was referred to me by a close friend.  that's who I'm seeing now.  I had it in my head that I wanted to try Armour and before I even brought it up, he suggested it after hearing my story.  I've only seen him twice, but am impressed with his attention to my problems and wanting to hear my story.  The others pretty much just didn't care.  It was more of a get me in, give me something to shut me up and get me out type of thing.  He told me that he didn't expect me to stay at the dosage I'm on right now, that over time your thyroid needs change and that he expected an adjustment to be needed in the near future.  I will definitely talk to him about the labs you mentioned.  He's been really great about responding to my emails and answering any concerns I have.  You are a wealth of knowledge.  Thanks for your suggestions.  I've had a concern about my Ferritan levels and am glad you mentioned that.  I read somewhere that almost everyone's Ferritan levels are off and it's one that is rarely tested and a lot of people tend to be anemic, but it's not found because that test isn't done.  shaking my head.....
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Avatar_m_tn
Hashi's can show up as high levels of either, or both, TPO ab, or TG ab.  So both tests should be done to confirm/rule out the presence of Hashi's.  Knowing if that is the cause will explain any need for increasing dosages of thyroid meds.  

As for ferritin, hypothyroid patients are frequently too low in the range for Vitamin D, B12, and ferritin.  Low iron will frequently show up as low ferritin, before showing up as low serum iron levels.  Low ferritin can inhibit the effect of thyroid meds, so it is important to test and assure high enough levels.  Here is some info I found on recommended levels.  

"FERRITIN test: Measures your levels of storage iron, which can be chronically low in hypothyroid patients. If your Ferritin result is less than 50, your levels are too low and can be causing problems…as well as leading you into anemia as you fall lower, which will give you symptoms similar to hypo, such as depression, achiness, fatigue. If you are in the 50′s, you are scooting by. Optimally, females shoot for 70-90 at the minimum; men tend to be above 100."
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200220_tn?1361955154
Is dizzyness a part of the hypo symptoms.  I have asked before on here but this is the first time that I have noticed it called a hypo symptom.  Da, it just clicked in my mind.  I have had a little over the years but recently I have had 2 bad attacks of it.  I had a CT and nothing showed.  The ear doctor said it was probably thyroid related.  I am now in the second attack.  It started yesterday.  I also had my husband check my sugar and it was 134.  I looked on line convinced that I was getting diabetes (no one in my family has ever had it).  Well I found out that blood sugar problems can also be thyroid related.  I am going to a new doctor on the 25th, he was recommend by someone on this list and hope that he will clarify all this and help me to feel better.  Iwas taking 5mg Crestor and realized the terrible leg cramps and muscle pain and extreme fatique was being caused by it.  I stopped and the cramps stopped and the fatique got much better.  My thyroid is not straightened out yet but I am in hopes that this doctor will test what is necessary and help by symptoms and not by tsh only.  Thanks
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Avatar_m_tn
Have a look at this link on hypothyroid symptoms.  It ijncludes vertigo as a symptom.

http://thyroid.about.com/cs/basics_starthere/a/hypochecklist.htm
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1797743_tn?1389217285
I feel for you.  There are so many symptoms that I had and would go to my Primary Care doctor only to be told that they were not thyroid related.  You would be amazed, and I'm sure you will be after you read Gimel's link, how many things are associated with Thyroid.  That's why I love this forum.  Good luck!
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