Sub-clinical Hyperthyroidism

[MamaWink]

Hi everyone - the thyroid can be a mean beast! And the endocrine system is complicated. I was diagnosed in 2017 (not Graves) and after a year under the endo my carbimazole dose was fixed at 5mg and 10mg on alternate days. I was discharged to GP care. After that, every 6 month blood test showed TSH and T4 in normal range until early 2021 when I had to start taking Anastrozole after surgery for oestrogen receptive breast cancer. I soon became hyper again and carbimazole was increased by GP to 10mg every day. After 6 months TSH and T4 were normal again, so back to the 5/10mg regime. Soon hyper again. GP asked for advice from endo and increased dose then I became hypo so decreased to 5mg per day. In February I was in A&E with chest pain, very high BP and fibrillation. Emergency doc had thyroid expertise and said hyper had caused symptoms. Now I adjust the dose myself based entirely on how I feel. I know when I'm hyper because I have far too much energy, can't sleep and feel too hot. My GP is happy for me to adjust my dose so that I feel well but monitors bloods every 2 months. The endo is not concerned. There seems to be such wide variation in blood test results among hyper patients and I have come to understand that only I know if I'm feeling normal. The biggest danger is heart damage and my GP gives me a prescription for Propranalol to take if I need it. It takes a degree of confidence to reach this point but since my A&E experience I decided I was probably better placed to know how much Carb I need, with the caveat that my GP does monitor me closely. 🤞but I've felt normal since March, sticking with 5/10 mg on alternate days and not over-worrying if blood results aren't perfect. My T4 is normal, TSH goes up and down but mostly near normal. Hope this helps some of you 🤗

[PurpleNails Administrator]

Welcome to forum

Have you had an uptake scan to confirm your hyper is from a toxic goitre?

Have you had all thyroid antibodies tested? TSI, TPO, TG, Trab?

Adjusting carbimazole based on TSH & FT4 is issue because FT3 is the active hormone & when thyroid is dysfunctional it can be unpredictable.

I understand the temptation to tweak dose by symptoms too, but symptoms can be deceptive. I know when it’s not right, but sometimes I’m way off on the level or the balance of FT4 : FT3.

Carbimazole full effect can take 6 weeks, because it lowers production not existing levels.

I’m surprised you are tested 6 monthly. Most who are on long term carbimazole are tested 6 weeks after a dose change & 12 weeks when consistently stable.

Propranolol lowers FT3 so taking it inconsistently is likely complicating your thyroid levels.

Have folate, ferritin,B12 & vitamin D been tested?