Thyroid UK
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What should blood test results look like

It seems there are different views on this and the American amounts look different. Could someone point me in the right direction to see the ranges for TSH, FT3 FT4, RT3 and RT4. What would also be good is if anyone knows the optimal levels, I already know not to take any notice of the TSH, mine is really low because of the amount of Thyroxin I take. Thanks in advance.

20 Replies

As you say TSH is irrelevant and even more so if you have Central Hypothyroid


Free T4 and Free T3 should both be in the upper quadrant of their ranges

hence on the usual UK range for T4 where 24 is the top a free t4 of 19 or 20 is optimal

but some patients especially if they originally had Graves Hyperthyoid will only feel OK if their Free t4 and Free T3 is right at the top of the range




Omg i had graves hence the removally so should i b wantin my level right up the top


Theres old Swedish research which several of us are trying to find but which my husbands case has proved

After Graves your body is so sensitised to such high levels of thyroid hormone it can never again cope on so called "normal " levels

So your Free t4 and Free t3 must be way at top or even over the range while your TSH may be totally supressed

Also post Graves all your vitamins and minerals will have been totally trashed well into scurvy and beri beri hence adrenal dysfunction and low ferritin

You need to take at least 2000mg vitamin C plus iron 4 hours away from thyroid meds and a really good multivitamin like Lamberts before bed

Because your ferritin is likely on the floor your body cannot even utilise levothyroxine because you cannot convert it into the T3 all your cells are screaming for

Hence the levo forms a toxin in your body

You really need just T3 liothyronine in the interim several months it will take to restore ferritin levels to HALFWAY in its range

There is research to support all of the above so go back to your doctor and request tests for




Vit d3

all should be halfway in their ranges

You need as much rest as possible and a lot of help and understanding from family and friends and not have to work while your body recovers

After that most post graves people find that they are only really well on NDT and not levothyroxine because it contains T1 T2 T3 T4 and calcitonin which a normal thyroid would have produced

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Omg that is very i had thyroid removed 6 yrs bac got put on antidepressants due to anxiety now iv learnt 5 year down the track n off antidpressants but feel off the plant..mood swings mental changes ahhh..will c doc for those test just had meds levels not enuf..way too scared to do myself..please keep intouch


Exactly the same as my poor husband

He was well into Myxodeama madness with a TSH of 2.9 and a free t4 of 19....... 6 years after thyroidectomy

It took another 12 years going nowhere on levothyroxine ,anti depressants etc before he finally got NDT and now age 72 is 95% fit and well

Stand your ground with your GP and if nessecary self treat


Hi i am wanting to no the best way to increase my ferrtin please as i think this is the stem to al the problems im body idnt converting t3 an liver is fuctioning properly..n i think b due to cels n oxgen not gettin to the organs properly could u share wat us done to heal


Hav been doc an ferritin was done feb 3 level 75 ug/l 20 -200 is range


Bexworkforall, Welcome to the forum.

There are no universal ranges for blood results, they vary from lab to lab depending on analysis machines used and vary across regions as they are based on a median of population results.

You need to know the lab ref ranges for your results. Generally FT4 in or near the top 75% of range and FT3 in the top third of range is desirable but some people need results higher or lower in range to feel well.


Be aware when you see ranges being quoted for anything that European and American units of measurement are often different. Some people don't bother quoting units of measurement, they just quote numbers. Personally, I think this is a very dangerous practice!

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This is especially true where the numbers are similar enough to be confusing. For example, B12 can be in pg/mL (picograms/millilitre) or pmol/L (picomoles/litre) - but the numbers would be close enough to make it impossible to be sure.

We also see confusion between Free T3 and Total T3 - a low FT3 result could easily be mistaken for a high Total T3. The numbers are close enough - but the units of Total T3 are a thousand times the size!


rt3 should be at the bottom 1/4 of the range. In my case, i cannot get my ft4 up to the upper part or even in range without too much rt3 being made. So a high in range ft4, may not work for you. Also, symptoms are more important than labs. I have found that they don't correlate well with symptoms.


Agreed. Labs are only a guide, and 'optimal' is when all your symptoms have resolved. Optimal has nothing to do with numbers, it's how you feel, and it's different for everyone.


Why do people keep insisting that the numbers have to fall in a certain place and magically you will feel well?!!! Initially, they may tell something, reverse t3 or low ft3 and high ft4 may tell something, but if you have thyroid hormone resistance, they tell nothing. They sound like all my idiot doctors who didn't listen to me. "oh, your labs look great, so you must have another disease..we will send you to 10 more doctors".


Yup. Exactly! And the worst is : your TSH is in range, so you're better. I'll tell you when I'm better, mate, you Don't get to tell me!!!


Y is it some doc dont test rt3 as im nz and they dont know rt3


How or what do i ask for too do my rt3 hav read a bit bout this


You will have to get it done privately, order your own labs, pay yourself, if you are in the UK. In the US, you just ask he doctor to do it.


Im in nz and no one looks at that n im not sure how or wher my range should b


Very helpful everyone, thankyou.


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