How low can TSH levels get before you should be... - Thyroid UK

Thyroid UK

137,148 members160,828 posts

How low can TSH levels get before you should be concerned?

LJG84 profile image
3 Replies

Hi Everyone,

Hoping for a few pointers on TSH levels after starting T3 treatment due to failing to convert. My blood results and medication changes are below (with full history summary at bottom if needed).

Should I be concerned at how low the TSH has now fallen to? I've never suffered symptoms of an overactive thyroid and feel the medication I am on now is ok. Not sure if I'm worrying only due to doctors concerns (scaremongering?) - should I drop my medication if I feel ok and it's working?!

22.12.17 on 175mcg T4 / NO T3

TSH 4.23 (0.27-4.2) / FT4 23.59 (12-22)** / FT3 3.8 (3.1-6.8)

21.02.18 on 175mcg T4 / 20mcg T3

TSH 0.04 (0.32-4.2)** / FT4 20.8 (12-22) / FT3 5.6 (2.7-5.7)

14.03.18 on 175mcg T4 / 20mcg T3

TSH 0.01 (0.32-4.2)** / FT4 15.7 (12-22) / FT3 4.4 (2.7-5.7)

28.03.18 on 150mcg T4 (reduced 15.03.18) / 20mcg T3

TSH 0.01 (0.32-4.2)** / FT4 15.2 (12-22) / FT3 4.3 (2.7-5.7)

19.04.18 on 150mcg T4 (reduced to 125mcg 3 days/wk on 11.04.18)/ 20mcg T3

TSH 0.03 (0.55-4.78)** / FT4 16.4 (10.0-18.7) / FT3 6.6 (3.5-6.5)**

Unfortunately I did take my pills an hour prior to this test due to forgetting to take them afterwards so this may have altered the results slightly.

HISTORY:

- diagnosed 2001/2002 following glandular fever, eventually ended up at 200mcg T4 daily

- 2011 Vitamin D deficiency diagnosed

- T4 gradually reduced after 2011 until bloods showed over limit/high TSH with ok T4 levels from 2015. Appears to show beginning of failing to convert.

RECENT HISTORY:

- Sept 2017 started seeing endo and she raised T4 back up to 200mcg, blood work after 4wks showed: FT4 29.95 (12-22), TSH 1.15 (0.27-4.2) and FT3 4.6 (3.1-6.8). T4 then reduced and T3 added as above.

- Feb 2018 started supplementing vitamins and went gluten free.

Written by
LJG84 profile image
LJG84
To view profiles and participate in discussions please or .
Read more about...
3 Replies
LJG84 profile image
LJG84

Great thanks for this. What are the best ways to deal with GPs/Endos who believe it should be higher (0.5-1)?

Andyb1205 profile image
Andyb1205 in reply to LJG84

Well refer them to the guidelines for treating central hypothyroidism, TSH is ignored and dosing is to bring FT4 in upper half of range and tuning according to symptoms. Hence TSH is only relevant in so far as it accurately predicts the level of thyroid hormones, works for most but not all patients. Your Frees do seem to be on the high side but as you said you may need to retest after fasting.

DeeD123 profile image
DeeD123

Maybe your tests could be a bit longer between. 6/8 weeks could give you a better picture before you change dose as it may give your body chance to settle more

You may also like...

Low TSH on no meds - should I be concerned or not?

- 175) TSH X 0.13 mIU/L (Range: 0.27 - 4.2) Free T3 5.03 pmol/L (Range: 3.1 - 6.8) Free...

low FTx levels but severely suppressed TSH

15 hours I see: TSH 0,009 [0.27 - 4.2] FT4 14,5 [12 - 22] FT3 4.9 [3.1 - 6.8] While FT3 is a bit...

How much does FT3 affect how you feel? Can a small drop make a big difference?

before levo: TSH 5.36 (0.27 - 4.2) FT4 13.5 (12 - 22) FT3 4.6 (3.1 - 6.8) ** NHS bloods showed my...

Should I be concerned about low TSH?

(pmol/L 3.1 - 6.8) I take approx 90 mg T4 daily plus 5mg T3. Since the TSH is not actually...

A little worried again about my TSH...

0.27 - 4.2 FT3 5,9 3.1 - 6.8 FT4 17.6 12 - 22