Thyroid UK
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Anyone else know nothing about t3 t4 levels?

hi im new to this site and didnt even know i had a thyroid problem until my doctor spotted my goitre! had been told for years that my severe tiredness was cfs! I had a full thyroidectomy in july of this year and am 100 micrograms of levo. Nobody has explained anything to me really about what happens now, how i go forward or if i should be feeling better, which im not. I have no idea what t3 or t4 levels are ( only know about these from reading this site) and all i want is to feel better instead of wanting to sleep! and ive piled on weight :( Any help and advice much appreciated x

9 Replies

It is unlikely that 100 micrograms would be enough levothyroxine for someone needing full replacement.

My first bit of advice is to get hold of your blood test results. You are entitled to them:

My second bit of advice is to have a good read around the main Thyroid UK site.

Never blame yourself for not understanding any of it. Initially getting hold of some of the ideas isn't too difficult. But the full complexity is rarely appreciated by anyone. Except maybe some researchers and some people who have been through the mill.



Hiya. I had the same operation in February and I too was just told to get on with it. I started on 100mcg levothyroxine and I'm now on 112.5mcg. I had 2 weekly, then monthly, then 6 weekly and now 2 monthly blood tests to monitor my levels.

I'm no expert at all and I hope someone can explain what t4 and t3 are exactly. I THINK t4 gets converted to t3 so the levothyroxine is t4 and then the body converts it to t3 so it can be used.

I would think you should be feeling better each day and if not, maybe you are not on the right dose or maybe not converting it. I also had vitamin D levels checked and also tests for anaemia- maybe you should ask for these too?

Sorry I haven't been much help. I do remember feeling totally exhausted but in general each day I felt a bit better.

Take care


I've had one blood test since July. Was told no action required and given another months dose of levo. I'm starting to think my doctors don't know how to deal with me :(


Hmm I was told by my surgeon that it can take 6 months to get the right dose. Also it's helpful to get a print out of your results each time and people on here can help you decipher them. Anyway, if you are still not feeling well, I would go straight back to the doctor and tell them that- they should be aiming to get you feeling well. I hope you can get it sorted.


Ty! I'm due at the doctors on Thursday and am hoping to get some answers x


You are right - T4 is changed to T3 which is used directly in the cells. Most people get right on T4 but it takes quite a long time to get to the right dose and for the body to adjust to it. TSH is a measure of the body calling for more T4. It is therefore used to measure how much T4 you need. It is all influenced by body cycles and adjustments, vitamins etc. Be patient but makes notes all the time (a log of how you feel, symptoms you notice etc) and get copies if all test results. With time you will understand more and looking back at results, doses and how you felt is a useful guide forward. Occasionally there are people like me whose chemistry is broken somewhere (not well understood) and whose body cannot convert T4 to T3. No matter how much T4 I took, I was never any better. Because there was lots of T4 floating around the TSH was very low and not calling for T4. Doctors concluded therefore I was OK! Once I found a specialist who would listen I started trying T3 and got immediate improvement. However it reached a limit. I learned that damaged chemistry in the body can cause it to make a reverse version onT3 (rT3) which blocks entry to the cells. I pursuaded the specialist to let me try pure T3 and stop T4. Within 3 days I was a different person! I have not looked back. I have to take doses exactly on time (3 a day) so it is more complicated. Hopefully you will never need this but perhaps this information will answer some of your questions.


As Rod says look at the Thyroid UK website which has loads of information about thyroid problems generally, which tests you should have and specifically explains about T4 and T3: and

Jane x


It's taken me nearly 3 yrs post TT to get my levels right and now I feel great. I'm on 75mcg levo thyroxine and finally the weight is moving too. Persevere and don't ignore what your body is telling you even if they do seem like "weird symptoms" it's all relevant. Good luck.


Ty RonnieG! It's great to have support from people like yourself on this site as it can feel very lonely and an uphill struggle just trying to feel "well". I'd just like to feel my age ( 42 years young lol) instead of 180 and taking afternoon naps!


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