How to Understand Test Results


I was diagnosed with Hashimotos in May and started taking 25mcg of Synthroid each morning and then 6 weeks later increased to 50mcg each morning. I recently read T4 medications do not work? Last week I had blood tests done. The results are

T4 (Free) 16.3 pmol/L ( 12.8-20.4 )

T3 (Free) 4.3 pmol/L ( 4-6.8 )

TSH 5.5 mU/L (0.4-3.8) This TSH result was asterisked as being high by the pathologist?

I have a new Dr, the original one apparently did not do all these tests. If any-one has any feedback on these results that would be great, thank-you. It would be good to have a better understanding before my appointment.

44 Replies

  • Hi there,

    Can I ask how you are feeling on the T4, any better? Or did you not feel ill in the first place.

    AFter two years of being diagnosed with Hashis I came to realise quite quickly that if I feel well then the medication was working.

    It is going to take perhaps another 6 months before your dose levels out to where it needs to be, and unfortunately it is not a quick process.

    You may want to consider having your ferritin folate, vitb12 and vit d tested.

    I did not do this early enough into my treatment and only found out in March this year that my vit b12 was low and my vit D was terribly low, these can also make you feel unwell. In fact very similar symptoms to Hashis

    Your new doctor has ordered some good tests as over here in uk the labs refuse to test T3 so I would say trust you doctor and make sure to discuss how you feel what you symptoms are. There is a symptom checker you can use if you click on Thyroid Uk in the centre of the page at the top. It helped me realise if I was getting any better or not as I filled a new one out for each gp appointment.

    It is a bit of a roller coast with Hashis as you occasionally get flare up of the thyroid and this can bring you down for a few weeks and then you come back up again.

    Write a list of questions for your gp, I always forgot mine due to being a little foggy headed. You can ask lots of questions on this site, there are some excellent members who can advise you and we all tend to share our experiences in the hope it brings some light.


  • Hi, I did not feel good, I was extremely tired with no energy. My tiredness is not as extreme and my energy is still low, so I do not feel Synthroid is working properly. Also I have really been careful with diet etc and still not lost anything which is disappointing. In May I was also diagnosed Diabetes 2 (taking Metfomin), have had a recent flare up of Raynauds and new blood tests show ANA positive 1:640 homogenous, possible lupus. As a "newbie" it is hard understand what is going on :)

    I am glad you think my new Dr is good that confirms what I felt. Yes, he did test Vit B 250pmol/L (170-800) and Folate(serum) 33.9 nmol/L (9-45) so they are both within normal, Vit B12 still on low side though. He is also tested iron 9umol/L (10-30) and iron saturation 13%(16-45) both of those came back as low. Vit D was not tested so I shall look at that.

    That is a great idea about the symptom checker thank-you. I do tend to get foggy at the Dr's especially when I am also trying to understand what he is telling me.

    Thank-you, your advice has been very helpful. It is a great site and once I get a hold on things I hope I can also share useful information. Have a great week-end!

  • It feels like the T4 is not working almost certainly because you're not on a high enough dose. Remember that this forum is full of people for whom T4 stopped working (after years of being well) or for whom it never worked at all. But as Treepie says, T4 works well for over 80% of people ONCE THEY'RE ON THE RIGHT DOSE. Your TSH is still far too high, and both fT4 and fT3 are low in range, hence you don't feel well. You will probably need to increase your dose and keep increasing until you feel overstimulated (you should know it when you feel it). Ask your doctor for an increase to 75 mcg, retest levels after 6 weeks, then possibly increase again to 100 mcg depending on whether fT3 is still in range and how you feel.

  • Hi Hose 1975,

    I feel that my dose is too low too. After reading your advice I am feeling much more confident about asking for an increase dosage, should I need to do so. Thank-you for your explanations It feels so good to be gaining a better understanding of this.

  • You should ask for an increase now, as your TSH is still well over range. Most people seem to find that keeping their TSH around 1.0 works well for them, but some (like me) need it below the bottom of the range. However, if you find that you feel well with a TSH of 2.0 and your other bloods are in range (probably high in range), then that'll be what works for you.

  • Thank-you Hope 1975. My appointment is not for another 2 weeks, the earliest I can get.

  • Hang in there. How you're feeling now is still a lot better than how you were feeling before treatment. Yes, your medication levels aren't optimum but you're getting there.

  • Thanks :) I have been so cold recently and only just realized it is likely to be from my low thyroid. With Raynauds I am supposed to be staying warm so I shall call them on Monday and see if they can change the prescription earlier. Thanks for the encouragement :) Yes it is getting better and I am feeling much more at peace with it all since joining this community :)

  • Artea, how is your diet?

    Try eating a very high protein and virtually NO carbohydrate diet.

    I have hypothyroidism and cancer and now am experiencing great energy levels and good sleep and a huge reduction in cancer cells in my blood. Was supposed to die in 3 months time (March to April), since I refused chemo in Oct. 2015

    Have helped myself and found and am living on vegan protein, i.e. Nuts and Dark Greens and Organic Wheat Grass Powder in water. 8 heaped teaspoons twice daily.

    God Bless


  • Artea, Synthroid will work when you're optimally dosed and your vits/mins are good. You need dose increases to increase FT4 and FT3 which will bring down your TSH. Most people will be comfortable with TSH just above or below 1.0 but some need it lower, or even suppressed <0.03 for FT4 and FT3 to rise enough to feel well. FT4 should be in the upper quadrant of range and FT3 in the top third.

    B12 250 is very low, neuropathy can be experienced <500. 1,000 is optimal. Supplement 5,000mcg methylcobalamin sublingual lozenges, spray or patches for a couple of months to boost levels and then maintain at 1,000mcg. Take a B Complex vitamin to keep the other B vits balanced.

    Ask your GP to test ferritin and vitamin D, both are commonly deficient/low in hypothyroid patients.

    Adopting 100% gluten-free diet can help manage Hashimoto's and reduce antibodies.

  • Hi Clutter,

    Thank-you for the Synthroid information, that is a good guideline to have. Re my Vit B12 results what excellent information you have given me. I had been trying to research this myself as I often have tingling, numbness and extreme cold in my toes and fingers I also had Raynauds and chilblains as a teenager and after decades of no Raynauds symptoms I recently had a Raynauds flare-up.

    So I shall follow your Vit B advice :)

    He did not test for Vit D but did do an iron study test.

    Results were:

    Ferritin: 24.0 ug/L ( 20-350 )

    Iron: 9umol/L ( 10-30 )

    Iron Saturation: 13% ( 16-45 )

    Transferrin: 2.9 g/L ( 2-3.2 )

  • Artea, ferritin is very low, optimal is halfway through range. Supplement iron and take each tablet with 500mg-1,000mg vitamin C to aid absorption and minimise constipation. Take iron 4 hours away from Synthroid.

    You can't be a little bit pregnant or a little bit gluten-free. The tiniest bit of gluten can upset your gut so try 100% free for 2-3 months. If gut doesn't improve reintroduce gluten.

    Only ever eliminate one food at a time when checking for irritants. Eliminate for 2 weeks, reintroduce and see what happens then eliminate the next food. Otherwise you'll never be sure what food type is a problem.

  • Thank-you Clutter re the supplementary vitamins. I do always wait the 4 hrs after Synthroid except for Metformin (diabetes 2) which Dr told me to take an hour after Synthroid. I take a multi-vitamin each day also juice beets, carrots and apple each day and eat 1-2 kiwifruit. So with the supplements that you have suggested do you think I should cut down on what I am already doing or is it ok to combine them all. I am wondering if over dosing on Vit C is a possibility?

    That makes perfect sense to only eliminate one food at a time and yes, I have never experienced being a little bit pregnant either :)

  • Artea, there's very little of anything in a multi-vit so you won't overdose if you take it in addition to those I've suggested. If you take too much vitC your bowels become loose but iron has a constipating effect so they'll balance each other out.

  • That is good to know Clutter, thank-you! Thanks to this community, I woke up this morning feeling more confident in moving forward :) What a great resource this community is!

  • Re gluten free, I have cut back a lot on wheat and milk as I have felt one or both of these maybe affecting me negatively. Since cutting back on them I have noticed much less hardening of the stomach, bloating and less gas. As I said I am not sure yet if this is because of having less wheat or having less milk. So I have not yet gone gluten free but if it helps it would definitely be worth it.

  • I would have a read of Paul Robinsons blog. T4 doesn't work for me or for any of my family. We all are hashis hypo. T3 is more fitting for us.

    I paid for private bloods as it's a fuller picture. But personally I think it's importabt to listen to your body. Your symptoms speak louder.

  • I too use Pauls book and take t3 and t4 however only 4 months into treatment may be too soon to flip into taking T3 personally I wish I had switch sooner but if T4 could work it is a much easier option.

  • Thank-you I feel much better about this all already. It is also good to know that if effectiveT4 is simpler.

  • Thank-you Berlidders I shall look at his blog. My Dr has done a number of blood tests but because there are other things he is looking at I am not yet sure how they relate. Listening to your body makes good sense and I shall try to be more aware and note down "oddities" as they happen. I am going to the blog now, thank-you for the link :)

  • T4 works for around 80% of hypothyroid folk but it will be many months before you will know you are in that group. Your TSH is still too high and you will need to gradually increase the dose every 6-8 weeks and retest. Most people feel well at around 1 or below.

    Your B12 is too low and needs to be at the top end of the range as your illness depletes your vitamins. You cannot a toxic dose as you can with Vit D3 as Excess B12 is excreted in urine.

    My GP told me it would probably take as long to get well as it did to become unwell.

    As I was 69 and as I can look back with hindsight and identify symptoms nearly three years ago this was not welcome news. 15 months on I am much improved on T4 , plus B12 and quality multi vitamins but still have some symptoms.

    There is not a quick fix unfortunately.

    Some folk take T4/T3 others T3 only and others take Natural Dessicated Thyroid which we have just learned Hilary Clinton' s doctor prescribes for her.

    This is not just a matter of preference as T4 or T3 or NDT can make individuals worse and experimentation is needed . Sometimes it needs a change of brand as fillers etc can give allergic responses,

  • Treepie,

    Do you all know of anyone who has successfully switched from T3-only to NDT?

    A year ago I switched from NDT to T3-only because I was sure I wasn't converting the T4, although my tests would consistently show that my lab numbers "were within test range." I have spent the past year very meticulously addressing my diet (sugar-free, gluten-free); removing chemicals (fluoride, preservatives, etc.); supplementing all vitamins and minerals optimally; AND adding USP progesterone. So I am hoping now that MAYBE I can convert the T4 in NDT...

  • I cannot recall anyone but i suspect there is .Suggest you start a new string asking the question.

    Good luck

    Folks on here reckon Methylcobalamin is best form of B12.I was surprised to learn there are 3/4 formulations.

  • Thank-you Treepie. In retrospect I also think I have had this for 3-4 years. That is good to know about T4 working for 80%, I shall keep that information in my think tank :) I will also get some Vit B12 now I know it is not toxic. I am presently taking a daily multivitamin and a magnesium supplement. Looks like more patience on my part is needed. It is good to know that you are turning things around and your health is improving.

  • You should be aiming for a TSH of around 1 before you would expect to feel well (although some people need a TSH well below 1 to feel well), so you will need a higher dose of synthroid. Your T3 and T4 results should be in the top quarter of the range. Your t3 result is near the bottom of the range so you have a way to go before that is right. If your thyroid is not working at all then you would expect a dose of at least 150mcg a day, although some people need a lot more than that. Interestingly animals need much higher doses than humans - I once read that someone's pet dog was on 800mcg a day.

  • Hi eeng.

    That is interesting. I checked online here in New Zealand and they are saying .4 to 4.00 TSH normal range which is not making sense to me. Maybe NZ is behind current research.

    Your TSH around 1 makes more sense and hopefully my new Dr, who has not discussed these results with me yet will agree with aiming for around 1 TSH. I am still low on energy, cold, dry skin, hair loss, no weight loss etc. In fact I just looked at the check list of symptoms for hypothyroidism and I still have them all.

    I have only just joined this site and already I have learnt so much. Thank-you for your help eeng :)

  • It's the same here, but this is what patients have learned actually works. In the USA they treat people with TSH of 3 or over. In the UK, it's 10. Now someone has to be wrong.

  • I agree, it makes no sense. It is very empowering and encouraging to have this sharing of knowledge. Thank-you :)

  • Your B12 should be around 800. One thing to bear in mind is that within range is not enough. Ranges are now being looked at, and are often outdated. I hope you always get printouts of the results.

  • Thanks misty dog. Yes I do get the print outs and I had been pondering over them and researching them on the internet. But the most effective help I have had is from all of you who have responded to my questions here.

  • TSH stands for thyroid stimulating hormone - forgive me if I sound like a school teacher but sometimes going back to basics is helpful - and as its name suggests, it stimulates the thyroid gland to manufacture T3 and T4. Because your TSH is a little high, this also suggests it's doing its job. Obviously, it should be lower and this must be concerning for you but it could just be that it is now in the process of slowly decreasing. Unfortunately because your previous doctor didn't request the full battery of tests you don't have anything to compare the current result to. Perhaps if TSH test was done in the past you might've found that it was even higher than your current result. Have you ever had a TSH test done?

    Hopefully your doctor will want to explore and explain the possible reasons for your TSH being raised still but your T3 and T4 are now within the normal range so I hope you can take some consolation from this. Now that your T3 and T4 are within the normal range it could be that your TSH is in the process of gradually decreasing, having done its job of bringing your T3 and T4 into the normal range.

    The endocrine system, of which the thyroid is part, is governed by the hypothalamus and it operates on a feedback system. When your thyroid hormones are low, the hypothalamus communicates with the pituitary gland and the pituitary then produces TSH which in turn will communicate with your thyroid. I'm sure you can appreciate that it's a very delicate balance that will take time to settle. My best advice to you is to arm yourself with facts before you next see your GP and write down all the questions you have (write down the responses too!).

    I wish you luck on your journey. Don't be afraid to be demanding of your GP, it's your right to have a good service from him/her. Be polite but firm and insistent but you can only pull this off if you're well-informed, otherwise you won't know what to ask or which tests to ask for.

  • Basics is good, understanding is what I need, thank-you :) I will do that when I go to see him and as you suggested I shall have my facts and responses. I am not afraid to stick up for myself but when you have no knowledge of something it is hard to even now what question to ask. Having said that with all the help I have received tonight I feel much more positive and I have a sounder knowledge for which I am very grateful. Thank-you for your well wishes Noelnoel and all the best to you too :)

  • Glad to be of help and I hope I was able to give a little more clarity to your understanding. You didn't say whether or not you'd had a previous TSH test done

  • I do not know if TSH was tested before and I do not know by which test or tests the initial 2 diagnosis were done. I do know though that this was the first time the three tests (T3, T4 and TSH) were done together.

  • Ok, I see what you're saying. When you see your GP, please do ask whether or not it was done previously. Hopefully it was and then a comparison can be made between what it was then and what it is now

  • Will do, thank- you.


    The above link will take you to the main website of Thyroid UK. Have a look around as there is so much for you to read and absorb - hopefully it is helpful. Have you considered having your anti-bodies tested ?

  • Thank-you Marz. I have had an anti-nuclear antibody test done

    Results: Pos 1:640 homogenous, pattern associated with SLE.

    I am not sure if this is the test you are referring to.

  • Sorry I should have explained more. The Thyroid anti-bodies are Anti-TPO - and Anti-Tg. If you test positive for them then you have Hashimotos - which is the most common thyroid condition in the world......

  • You were clear in what you asked me and looking at my test results that was all I could find that mentioned antibodies, so I added them in the off chance they were relevant :) Yes, I was diagnosed with Hashimotos but I do not have those results.

  • Sorry - my mistake ! I should have gone back through this very long thread :-)

  • No worries :) A lot to read but it has all been very helpful for me. Hopefully it also will be for others who may have similar questions. Thank-you :)

  • You are undermedicated with a TSH at 5.5 and your FT3 is only just in range. Hopefully your doctor will increase your dose.

  • Hi Muffy,

    I agree and under medication would explain some of the symptoms I am still experiencing. Hopefully my dosage will be rectified soon.

    Thank-you :)

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