Hypothyroid for 20yrs but need help interpreting results, please?

Hi, from my profile you will see that I have a family history of autoimmune problems. In addition to both my parents and sister being hypothyroid I have close family members with vitiligo, type 1 diabetes and coeliacs so we feel up against it. For many years I have accepted the GP's management of my thyroid but in recent yrs due to vast increases in my weight (plus most other typical symptoms), despite careful eating and regular exercsie, I have started to really feel the need to do more myself. I have only ever seen a consultant once, when first diagnosed, I think this was because it was unusual that both my parents were hypothyroid (not related except by marriage!!).

I currently take 200mg of levothyroxine daily.

My latest blood test showed:

TSH 0.08

T4 22.2

T3 ok

I just had a letter asking me to repeat my blood test in 3 months and this was odd as normally it is anually or occasionally 6 months. Therefore I phoned to see what my results were but I don't really know how to interpret them. Any help much appreciated.

17 Replies

  • Hi,

    You're not alone! Many of us have a family history of autoimmune issues. Hypothyroidism is normally managed by the GP so referral to an endocrinologist tends only to happen if there is something the GP is unsure of.

    Without the specific reference ranges from the lab that did your tests, I can't be absolutely sure about your results. However, if I go by the ranges of my local lab, then your tests are indicating that you are slightly over medicated.

    The range for TSH would typically be 0.35 - 5. So at 0.08 you are well below range.

    The range for FT4 might typically be 9-19, so at 22.2 you are over the range.

    Both of those results suggest over medication. The fact that your T3 is ok, may be why your GP has not actually reduced your dose yet, but wants to re-test in 3 months.

  • Thanks for that quick response. Now I'm concerned that if they reduce my dosage of levothyroxine I'll put on even more weight, or find it even more difficult to lose. Is this likely to be the case? I certainly don't feel hyperthyroid!

  • When you went for your last test, what time did you take your thyroxine? If you took it too close to the time of the test, that could be why your T4 is over the range. T4 level is typically at it's peak up to two hours after ingesting. So it's best to leave as long a time as possible between taking your medication and getting the blood drawn. Ideally, if you take your thyroxine in the a.m., try to get an early appointment so that on the day of the test you can wait and not take it until after the blood draw. (You want your test results to reflect your blood levels at their worst, not at their best)

    With regard to the weight gain, it's impossible to say. We are all different. However, it's good to be aware that weight gain can occasionally also happen with over medication. Can't recall where now, but I read somewhere that approx 10% of people with hypERthyroidism actually put on weight rather than loose it. So there is a remote possibility that reducing your dose could help with weight reduction!

    Have you tried a low carb diet? Many hypothyroid people find this is the best way to control the weight issue - it works for me. There seems to be some connection between hypothyroidism and carbohydrate metabolism.

  • Thanks RedApple. I had my last blood test early in the morning, within an hour of taking my thyroxine. That could be the reason. I am just about to embark on the Atkins Diet as my weight gain is scaring me and careful eating and loads of exercise isn't working. Which of the Atkins books would you recommend to get me started?

  • I haven't actually read any of the Atkins books myself, but to get started you can learn a bit about it from their website. uk.atkins.com/program/how-i...

    I think the important thing is to research and educate yourself about which foods are high carb or low carb. The internet is full of info and recipes for low carb eating. I suppose at the most basic level, you could say if it's not meat, fish or vegetables, then it's probably high carb! Or the other way around... if it contains sugar, any form of grain or cereal or is starchy in nature such as potatoes, then it's high carb.

    A useful website is nutritiondata.self.com/ It has a great database that gives you the nutritional content of virtually any food you can think of.

    Low carb eating is not easy, and takes lots and lots of willpower, but eventually you get used to it. For me it's become a way of life (it's towards a year since I started) and I no longer crave many of the high carb foods.

    Good luck!

  • No No No..... you should NEVER have your thyroid function test done within a day of taking thyroid hormones. You're supposed to tstop taking them 24 hours before a test.

    This was suggested by Professor Anthony Toft, apparantly you get a spike when you take the thyroid hormones.


  • Ask your doc's receptionist what your lab ref range is for Free T4. Mine is 12 to 22 so your results would be fine in my area.

    Other things to consider:- has your pharmacist supplied you with a different make of levothyroxine? this can make a huge difference to some people.

    Also have you been taking iron supplements or anything that contains iron? or taking hrt? these make a difference to the absorption as does how you take meds, I know you have been taking them for years but a friend of mine recently said that she takes hers with her cuppa in the morning! I couldn't believe that she didn't realise that you should only take levothyroxine with water and wait at least half an hour before having anything else to eat or drink. Just a thought

  • It is only recently that I've started taking my thyroxine with water half an hour before breakfast. I;ve always been told to take it first thing but not without food or tea! The GPs need to stress this.

  • Just as a follow up, i've just contacted the GP to get my results and again I'm confused. He said they only did the tsh results as it was in range at 4.08 . Compared to my last result of 0.08 this is vastly different and I don't understand how I can take the same daily dose and the tsh can differ so much. I also feel much more tired and foggy brained. any explanations or advice on what to do next please?

  • Hi Jenny

    It could be that the change in the WAY that you take your meds has made a huge difference, it could be that for you it is better to take the meds with your breakfast, it might be worth a try changing back.


  • That is certainly worth a try. Is that sometimes the case for people?

  • Since it's the only thing you've changed, it seems reasonable to think that it might be the cause. Unfortunately such a lot of this is trial and error. :-(


  • I felt rubbish yesterday when I spoke to the GP as he said that my tsh of 4.8 was within range and could no way be responsible for me feeling fatigued and low or for not being able to loose weight, yet I'm sure I've read that most peolple need a tsh around 1 to function properly.

  • Jenny - have sent you a conv.... xx

  • Thanks so much for that information "Isanangel", it will be great to have to hand next time I go to the GP. xx

  • Ok more of an update, following a visit to the GP in November he suggested that I went to see a dietician and dermatologist, the dermatologist is still ongoing but the dietician was a complete waste of time. She basically confirmed that I was eating a healthy diet, consuming under the recommended daily amount considering the exercise I do but clearly struggling with my weight. I have continued to feel dreadful, tired, weak etc so I arranged with the medical practice to have a tsh, T3 and T4 test ahead of schedule. Last night I slept for 9hrs yet still had to sleep for 3hrs this afternoon whilst my kids were at school. I have received a phone call from the surgery this evening telling me to increase my thyroxine by 25mg to 225mg. It turns out my tsh was 15.9 (lab range 0.3 - 5.3). I just wonder how many people leave their condition management purely to their GP, as I feel I am constantly treading water and battling to feel well?

  • I used to take my thyroxine at night, had trouble sleeping. Changed back to taking in the morning sleeping better. Now back on HRT take this at night. I just hope they do not conflict.

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