Thyroid UK

Very confusing blood test results, can anyone help?

I was diagnosed with hyperthyroidism and Graves some years ago. I had a relapse over Christmas time and put back on PTU but I'm still feeling awful - exhausted, palpitations, lots of ectopic heart beats, hair loss etc! I have basically had enough & demanded more tests from my GP - apparently they are all "normal" but I've learnt that means absolutely nothing and would like a second opinion so would be grateful if anyone can help:


TSH 0.01 mU/L (0.35-5.5)

T4 26.7 pmol/L (10.5-20)


TSH 1.10, T4 12.9, T3 4.3


TSH 6.22, T4 13.7

(Reduced PTU from 100mg to 50mg a day)


TSH 3.76, T4 14.4

Serum B12 321 ng/L (180-900)

Serum ferritin 120.1 microg/L (10-200)

Liver function test:

Plasma total bilirubin 14 umol/L (3-17)

Plasma ALT 10 UI/L (10-45)

Plasma albumin 46g/L (35-50)

Serum iron 11.1 mmol/L (11-30)

Serum transferrin 2.46g/L (1.8-3.6)

Transferrin saturation index 21% (16-50)

I won't bombard you with my full blood count results as well but it did come back with Mean corpsuscular volume (MCV) 81.6 fl (83-105) "low" but apparently this is nothing to worry about??

Any advice would be massively appreciated

4 Replies

Low MCV can be indicative of iron deficiency anaemia.

Low iron seems to be an important factor in thyroid hormone handling in the body. So it is important on those grounds alone! Let alone all the other reasons low iron is bad.

I'd suggest that your B12 is low.

You represent that all too common patient - someone who was effectively over-treated on PTU (albeit it might have been important to start on a high dose), allowed to become hypothyroid, then wonders what on earth is happening. It's a hard path.



This is from a blog post that PaulRobinson wrote recently:

"Ferritin is key and it usually tracks transferrin saturation %. Serum iron is the least useful measure as it just shows current iron levels in the blood.

Thyroid patients need good (not low end of normal or barely mid range) ferritin levels and good transferrin saturation percentages. Serum iron is really not helpful at all on its own.

Ferritin can also be a problem. In cases of low iron, ferritin can sometimes appear to be high - due to inflammation. It is easy to spot because serum iron is low and ferritin is high and the thyroid patient either has multiple symptoms of inflammation or laboratory results that suggest inflammation. In these, latter cases, ferritin has to be ignored and the low iron treated as inflammation is also addressed."

Full blog link here:

I think the last paragraph applies to you. You have high ferritin, but your serum iron and saturation percentage is very low. This is backed up by you dropping below the range for MCV.

I agree with Helvella about the B12 as well. My last B12 test was 313 and I was deficient with a lot of symptoms. I had the MMA test to prove it. I am hyper as well and I believe (although can't prove yet, as I'm still on Carbi!) that my chances of remission are higher now I have treatment for my B12 deficiency. You must get your folate checked as well because they work together, I was deficient in that too. Some people have high folate, because it builds up in the blood with not enough B12 to work with, or because they have problems metabolising it (MTHFR gene mutations).

You could ask the GP to refer you for Active B12 test, details found in these 2 links:

And in case he fobs you off with the "you're normal" conversation, a study on functional B12 deficiency below:

Looks to me like they really overmedicated you on the PTU as well, you weren't even that hyper in Jan. So now your hypo, iron anaemic and possibly B12 deficient. No wonder you feel like a wet rag!

H x


Thank you so much for your help. Out of interest Hampster, could you tell me what iron, B12 etc supplements you take? There are so many out there, I haven't a clue which ones are best.

My GP must be getting so fed up of me asking for all these tests but I will ask for a folate test as well. I also had vit D done on 29/7 but results haven't come back yet - not sure if this is normal or they have just lost them, it wouldn't be the first time!


Is your doctor approachable? Your results so obviously suggest iron deficiency that I'm wondering whether you could try and get something on prescription? If not here is a recent question about this:

I take Spatone but I've only just started and don't know if it's working. I don't really know that much about the different options. Sorry!

On the B12 and folate front, I am currently on 2 weekly HydroxoB12 injections from my (very supportive) doctor, and a 5mg folic acid supplement on prescription.

I also take Jarrows 5000mcg MethylB12 sublinguals on every day I don't have an injection, and Jarrows B-Right (one a day), which is a B-Complex.

My personal opinion is that it is better to get a B12 deficiency properly diagnosed and treated, and then use the supplements as a supportive measure. I absolutely get the most benefit from the injections, I wouldn't be without them. I also get benefit from the sublinguals, but it would worry me to have to rely on them alone. So my reflex is to always say to people exhaust every avenue to get a diagnosis before you have to resort to self supplementation, it is expensive and will probably need to be maintained for life. B12 deficiency is another, possibly autoimmune based, medical condition, and shouldn't be taken lightly.

There are plenty out there who would disagree with me, and who have done perfectly well on sublinguals alone. Some out of choice, and some because their doctors simply wouldn't listen.

Even amongst those who have been diagnosed, there is a divergence of treatments that work for different people. Some people still prefer the CyanoB12 injections, many do well on HydroxoB12. Yet another portion only get relief from MethylB12, and seek out private doctors for MethylB12 infusions and injections. There is no "one size fits all".

I guess you have to decide for yourself which way you want to go with it.

Some more links to help you decide:


If you do decide on the Active B12 test please don't supplement until after you've had it.

H x


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