Low free T4 and free T3, normal TSH, low ferrit... - Thyroid UK

Thyroid UK

137,148 members160,828 posts

Low free T4 and free T3, normal TSH, low ferritin..

marielp612 profile image
5 Replies

Hello all, I have received great info here for myself but today I am asking on behalf of my daughter, age 34. She has long suffered with anxiety, insomnia, fatigue,cold extremities and most recently weight gain, despite being a runner. I appreciate any thoughts on her recent blood test results..

TSH 1.71 (.30-4.20)

T4 6.9 (5.1 -11.9)

Free T3 (2.9 ((2.3-4.2)

Free T4 .9 (.8 - 1.8)

Ferritin 18 (10 - 154)

B12 726 (no range)

Antibodies <1

My thinking is she is hypo and would benefit from treatment. Finding a Dr to treat is another story. Thanks in advance for your help!

Written by
marielp612 profile image
marielp612
To view profiles and participate in discussions please or .
Read more about...
5 Replies
shaws profile image
shawsAdministrator

Your daughter is hypothyroid but GP wont agree as her TSH hasn't reached 10. Her results are at the bottom of the ranges in the following when they should be nearer the top:-

T4 6.9 (5.1 -11.9)

Free T3 (2.9 ((2.3-4.2)

Free T4 .9 (.8 - 1.8)

Ferritin 18 (10 - 154)

thyroiduk.org.uk/tuk/testin...

thyroiduk.org.uk/tuk/about_...

I am not medically qualified but with such a low FT3 she wont have much energy as it is T3 that is needed in all of our millions of T3 receptor cells and is the Active Thyroid Hormone. A member will respond about her low ferritin level.

marielp612 profile image
marielp612 in reply to shaws

Thanks Shaws... it seemed that way to me. I plan to ask my endo about it when I see her on the 19th. I'm not expecting much of an answer. I wish I knew how to help my daughter.

Could be central hypothyroid (problem with hypothalamus or pituitary.

marielp612 profile image
marielp612 in reply to Angel_of_the_North

Thanks, I'll have to research central hypo and pituitary..

anonymous45 profile image
anonymous45

Hi there, as others have mentioned, she is at the lower end of the range - most knowledgeable healthcare professionals acknowledge that the top 1/3 of the range is where blood tests should be, especially in those suffering hypothyroid symptoms.

I myself had high-normal TSH, but extremely low fT4 and fT3 (just under the normal range). My antibody test was inconclusive, since I didn't have enough to warrant a hashimotos diagnosis, but they weren't low enough to rule it out.

Where T4/T3 is low and TSH is normal or close to normal, you should suspect and investigate secondary hypothyroidism. This is not the same as primary/hashimotos where the gland is destroyed by the immune system; instead the pituitary gland does not output enough TSH to keep T4/T3 levels in range, or the hypothalamus does not output enough TRH (which stimulates the pituitary to release TSH).

I would advise you/your daughter pick up a copy of "Understanding Thyroid Disorders" by Dr Anthony Toft, they're relatively cheap. It was very useful to me, and it has information and ranges which you can show your GP. The book is published by the BMA and any reasonable doctor should therefore take it seriously. My doctor agreed to trial me on Levothyroxine because of the info in this book, and I am now doing much better on 75mcg.

If pituitary involvement is the cause, cortisol levels should also be checked as a precaution.

Edit: Ferritin (iron store) levels are also on the low side. Iron supplementation may be warranted, OTC iron tablets could be useful, but your daughter might want to check with a GP to see if the prescription strength tablets would be better for her. Low iron causes fatigue in many ways, primarily because Haemoglobin relies on iron to function. It would be wise to get a Haemoglobin estimation done by a GP or a home test kit.

You may also like...

normal TSH and T3 but Low T4

9-10.5 FREE T4 INDEX (T7) 1.1 L Range: 1.4-3.8 T4, FREEB(ng/dL) 0.9 Range: 0.8-1.8 T3, FREE...

Low TSH with normal T3, T4.

Results 27 Jul 22 TSH 0.09 (lab range 0.27 - 4.20) FREE T4 - 23 (lab range 11 - 21.20) T3 - 5...

Low TSH with normal T4 and T3

Low TSH, normal T4 and T3

an endocrinologist I had switched from hyper to hypo so started on levothryoxine which I continued...

'normal' TSH and T4, low T3