My blood test results say, 'Below low reference... - Thyroid UK

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My blood test results say, 'Below low reference limit'.

Ellie-Louise profile image
12 Replies

These are my latest test results. I had everything checked this time round.

I think I knew before this that I wasn't getting enough Vit D so I'm not too concerned about that, and I'll just up my doses. The thing I don't understand and the doctor didn't mention the fact is my below range THS level. I take 75mcg Levothyroxine very late at night (ok! for late, read early hours) before bed.

Serum TSH level - 0.31 mu/L (0.35 - 4.94) Below low reference limit.

Serum free T4 level - 13.9 pmol/L (9.0 - 19.0)

Serum vitamin B12 level - 606 ng/L (150.0 - 883.0)

Serum folate level - 3.4 ug/L (3.1 - 20.5)

Serum ferritin level - 50 ug/L (22.0 - 275.0)

I would love to know if these results are and look OK, or should I be doing anything to change them please? Thank you so much. x

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Ellie-Louise profile image
Ellie-Louise
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12 Replies
Greenwall profile image
Greenwall

Hi. Below low reference limit, just means they are worried you're going hyper. However, I'd be happy with these results, but the big question is: Do you feel well, or do you still have symptoms?

Ellie-Louise profile image
Ellie-Louise in reply toGreenwall

I have always felt well, apart from bouts of being frozen, joint aches (come with age don't they? I'm 70) fine thinning hair, since I came off the pill in 1976, infertility, and the other usual things. But in myself I feel well enough and always have done really.

steviecat profile image
steviecat

Hi Ellie. Did you take your thyroid meds in the evening before your tests? If so, it will probably have affected the results. Most folk here suggest staying off the meds for 24 hours before tests. (Some suggest 12 hours). If you did take your meds, it will (probably) have made your results look more startling... However, Greenwall is right - do you feel well? It would help enormously to have a result for Free T3, because that is the crucial one. Armed with that number, you would then be pretty sure if you were over medicated or not.

Ellie-Louise profile image
Ellie-Louise in reply tosteviecat

No, I never take it the night before my annual blood test.

greygoose profile image
greygoose

Once you are on thyroid hormone replacement, the TSH is irrelevant unless it goes high. It does not matter how low it goes.

On the other hand, if I were you, I would be concerned about my low FT4. It's just a tad below mid-range. I would want mine higher, and would therefore ask for an increase in dose. :)

Ellie-Louise profile image
Ellie-Louise in reply togreygoose

I upped it myself from 50 to 75 about a year ago because I thought I read somewhere that more helped with hair, I don't think it ever has though. I don't know how I'm supposed to feel because to my mind I feel no different to how I felt 10 years ago when I was diagnosed as borderline. That came as a complete surprise, but I've never been one of those tons of energy people, I'm a quite laid back and calm, things will get done when they get done, sort of thing.

greygoose profile image
greygoose in reply toEllie-Louise

Well, you might feel even better if you increased it again. :)

Ellie-Louise profile image
Ellie-Louise in reply togreygoose

Hmmm! Worth trying then, thank you. x

I could do that off my own bat and tell the doctor later if it makes a difference to me. I have actually got loads of pills because normally I get 3 months worth at a time. I had finished 1 pack, couldn't find any more so presumed I had taken them all and ordered another prescription. After that I found what I had lost, so I have quite a few packs. :D

greygoose profile image
greygoose in reply toEllie-Louise

You're welcome. :)

Phoenix605 profile image
Phoenix605

My last results were

TSH 0.05 (0.3-4.2) T4 23.3 (12-22) T3 4.8 (3.1-6.8)

TSH and T4 were both out of range but my T3 was well within and thats the important one and stopped the GP dropping my dose. The labs dont test T3 normally but should if you are out of range, they didnt so if I hadnt had a private test I would probably have had to dig my heels in. I also have vit deficiencies which make my conversion iffy so TSH has become irrelevant.

If you are a night owl did you have a late test also? TSH follows circadian rhythms so you may have been tested at a low point rather than an early morning high. Im guessing your GP has a clue, as some GPs would have tried to drop you with that TSH when you could do with bit of an increase.

Definitely give your dose a miss the night before as if you didnt you may also be getting a false higher T4 as a result and as your T4 isnt exactly high in range now that might also point to a pituitary issue causing the low TSH reading

Ellie-Louise profile image
Ellie-Louise in reply toPhoenix605

No, I never have my Levothyroxine the night before a test, and I was up early next day because I had asked for an 8:00am. test appointment.

Ellie-Louise profile image
Ellie-Louise

So do you think that I need to supplement with iron too?

They always seem happy enough when I give blood, the drop of blood they take always sinks quickly to the bottom of the tube, and the doctor didn't say anything about that, only that vit D was low.

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