Thyroid UK
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Under active thyroid -please help me understand my results and what to do as feel unwell

I am 46 and I have had an under active thyroid diagnosed since my eldest son was 6 months old. He's now 15. I had anaemia when pregnant. I am taking 200 mcg of thyroxine a day and have all the symptoms of under active thyroid still. My dose was reduced to 150 a few years ago but I felt terrible so asked to go back to 200 which thankfully my GP did do.

I have weight gain Inspite of running x5 a week and eating very little junk, feel cold all the time, foggy brain, low mood, lack of energy, dark circles, dry hair. I am not constipated (quite the opposite).

My most recent results

Serum free T3 level 5.7

Serum TSH level 0.03 mu/L

I wonder if I might have adrenal faitigue and/or intolerance of gluten also? How to find out? Should I ask for Vit B12, zinc, Vit B and magnesium blood test or just start taking supplements myself? For info I'm veggie but do eat fish.

I just want to feel better! Thanks in advance.

8 Replies

You need to get your iron/ferritin levels tested again along with vitd, B12 and folates.

I think you are maybe be a little over medicated but possibly due to low vitamins levels your levo is not working properly.

Moggie x


Thanks Moggie. Kind of you to reply so quickly.

Sorry I should have added iron was tested and in normal range.

If I am over medicated why do you think I am putting on weight? I have symptoms of underactive thyroid? Thanks xx


You say your iron levels are in "normal" range - have you got these results to post and was your ferritin levels done or just your iron?

You could be putting on weight because your body is unable to process the levo (T4) you are taking so it is not being converted to the active ingredient (T3) it needs to control your symptoms. Low vitamins will mess up this process and not matter how much levo you take these symptoms will not go.

Have a look around this website as will will explain things a lot better than I can.

Being over medicated can make you feel as unwell as being under medicated so you need to get a print out (with ranges) of all your latest blood results from your GP's surgery and post on here for advise.

You could also be right about gluten being a problem as many thyroid folk feel lots better when they take gluten out of their diet. Go to the post section and under "browse by category" you will find a "gluten free chats" section that you might find useful.

Moggie x


Thanks so much for listening and for suggesting ways forward.

I have got a full print out of my blood tests this morning.

I will have a look at the website now,

Haemoglobin estimation 142

Total white count 5.0

Platelet count 266

Red blood count 4.89

Hematocrit 0.410

Mean corpuscular volume 82.8fl

Mean corpusc haemoglobin 29.0 pg

Mean corpusc HB conc 351

Red blood cell distribution width 12.8

Neutrophil count 2.35

Lymphocyte count 2.00

Monocyte count 0.40

Eosinophil count 0.30

Basophil count 0.00

Erythrocytes sedimentation rate 2mm/h

Plasma C-reactive protein <2mg/L


Unfortunately these results mean nothing unless they have their ranges (figures usually in brackets after the results) as every lab uses different ranges. Can you phone the receptionist and ask for another print out with the ranges and then repost for people to comment.

I would definitely be going back and asking for the above vitamins to be tested because something is stopping your levo from working and now its just a case of finding out what.

Moggie x

p.s. Could you please use the "reply to this" button at the end of peoples answers as they then get an email to say you have made further contact, it stops people missing your replies to them.


Thanks Moggie. I will. Xx


Sorry forgot to explain something to you re vitamins.

You say your iron was in range but the NHS range means absolutely nothing to a thyroid sufferer, for example.

The NHS range of B12 is usually 190 - 900 (these are a rough guide), so if you are at 200 the GP will tell you all is well BUT a thyroid sufferer needs her B12 to be between 600 and 700 for her thyroid meds to work properly.

Same goes for your iron levels - a ferritin (iron your body has in storage) range is approx 15 - 300, so if you are at 20 your GP will say its fine BUT a thyroid sufferer needs their ferritin level to be about 70 for thyroid meds to work.

As you can see from the above a doctors "normal" means nothing to a thyroid sufferer and we should never take "normal" as an answer but ask for actual results to see exactly where we are in the "normal" range and if we have to supplement. I would NEVER supplement without getting tests done first because supplementing without knowing if you need them can be dangerous.

Moggie x

1 like

Hello Sandy12,

Thanks for your reply. That's what I was thinking too. No other family members with thyroid issues. Thanks again xx


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