Low TSH and High Thyroid Peroxidase >1300

[March2006]

Hi all, i'll be speaking to my Endocrinologist on monday but just wondered if anyone else has had a low TSH level generally between 0.01 and 0.08 and a high >1300 thyroid peroxidase level. T3 and t4 getting back within normal ranges. Currently on carbimazole 40mg. Looking for others experience asthere's not much info relating to this. I've no symptoms of hypothyroidism. Just all relating to hyperthyroidism with very high t3 and t4s.

[PurpleNails Administrator]

Welcome to forum. 

How long have you been on 40mg carbimazole? 

TPO signifies thyroid autoimmune in both under active and over active thyroid diseases.

Carbimazole should be prescribed for continuous hyper only, (not transient eg when diagnosed with thyroiditis. Very high TPO more common with autoimmune thyroiditis (Hashimoto’s)

To confirm suspicion of hyper Graves

TSI - Thyroid-Stimulating Immunoglobulin (signifies hyper Graves) or

TRab - TSH receptor antibodies (TRAb) (signifies Graves) 

TSH can remain low long after FT4 & FT3 correct to “normal”  in range levels.  

I’ve taken carbimazole 4 years TSH has never risen into range & stayed completely undetectable for majority of time.  (My hyper is not autoimmune)

[March2006 in reply to PurpleNails]

Thank you so much for replying, I've been on carbimazole for 6 months.

[PurpleNails Administrator in reply to March2006]

was 40mg the starting dose? Often it’s a starting dose but it get adjusted downward once levels in range.

do you have recent FT4 & FT3 with lab range.

[March2006 in reply to PurpleNails]

No it started at 15mg but still had high t3 and t4 , low tsh and very symptomatic. Increased to 40mg after 6 weeks. No I don't have t3 and t4 recent bloods just tsh and the antibody result

[PurpleNails Administrator in reply to March2006]

TSH very unreliable, adjustments should be by FT4 & FT3 not TSH.  concerning if doctors focusing on TSH only & not testing function & correct Graves related antibodies. 

You’ll need to know what your FT4 & FT4 to know of you should adjust carbimazole & by how much. Usually thyroid function is tested every 6 weeks until stable.  Do you have repeat test scheduled? 

Also important to test folate, ferritin, B12 & vitamin D.  These often become low when thyroid dysfunctional.  

Many use private finger print tests as doctors / labs can’t / won’t test everything required.  

thyroiduk.org/help-and-supp...