TSH quite high but T4 normal?: Hi everyone, on my... - Thyroid UK

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TSH quite high but T4 normal?


Hi everyone, on my latest blood test it showed that I have a low vitamin B12, a TSH of 4,5 and a free T4 of 18.

I know the T4 is normal in range, but is the TSH also normal? I suffer from really bad anxiety and tiredness, lack of appetite,.. so I would like to know if it would be worth it to ask my GP to further investigate it, as she said that everything was normal.

4 Replies

Laura221 How low is 'low' B12, and what is your Folate level? They work together and may need further investigation

TSH is too high. Are diagnosed hypothyroid and on Levo? If not, is this your first test o a follow up to a previous one to see if your TSH is rising or staying high?

My B12 is 193 ng/L, which is about 145 pmol/L. (however, that was my level in july, in january my level was 270 ng/L or 210 pmol/L, but my doctor still put me on injections due to my symptoms. I got my first injection last Monday).

I am not diagnosed hypothyroid. My GP just brushed it off and said I could take some spirulina. I didn't bother looking at it, because my lab range of healthy TSH is between 0,35 and 5, so I'm right in it. But while further looking on the internet, I found that a TSH of 4,5 is indeed quite high, that's why I asked the question if I needed to mention this to my GP, although my free T4 level is fine.

SeasideSusieAdministrator in reply to Laura221

Laura221 It looks as though your B12 is being addressed then.

What you really need is a full set of thyroid tests to include




Thyroid Peroxidase antibodies

Thyroglobulin antibodies

And it would be useful to have Vit D and Ferritin tested as well, then everything is covered.

It's very unlikely your GP will be able to get FT3 and TG antibodies tested but you can get everything in one test privately if you wish, with a fingerprick test


When posting any results, the reference ranges are needed because ranges differ from lab to lab. As you haven't given the range for your TSH and FT4, it's not possible to know if your TSH is over range. If it is then your GP should retest in 3 months to see if it rising or whether it's a one-off and caused by a non-thyroidal illness.

Most GPs won't diagnose and treat Hypothyroidism until TSH reaches 10, or if you have a below range FT4 along with a high TSH. Sometimes having high antibodies, which means positive for autoimmune thyroid disease, means that treatment will be started.

Thank you for all your replies. My TSH was 4,5 (0,35-4,5) and T4 18 (9-20,6).

I know the TSH is just within the reference range, but it just seems like a lot, and my level has always been between 4,5 and 5,5 within the last 2 years, which kind of worries me, because thyroid problems run in my family (hyperthyroidism)

My main symptoms are: VERY cold hands and feet, fatigue, depression, anxiety, memory loss, loss of appetite. AND a very, very tense throat. There is like a tension in my whole throat, and my thyroid feels very swollen.

I know that the weird thing is: I have mixed symptoms of hyper and hypo. The racing heartbeat would be more likely for hyperthyroidism, but my TSH indicates more towards hypo?

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