Quick background is I was diagnosed with ME/CFS and hypermobility in October privately by a rheumatologist. I have had 2 previous normal thyroid tests. Since Easter, I’ve had many horrible symptoms including a racing heart (135bpm resting) so was sent to A&E by my GP. I was told that everything was fine, it was just ME/CFS and asked my GP to refer me to a specialist clinic. During sorting this referral, my GP looked at my blood results and said I have “significant hyperthyroidism”. TSH <0.02, T4 72.1.
To go from being absolutely normal to this in less than a year just seems bonkers to me. As well as the hospital not even telling me in the first place. Could this be wrong?! I have been really ill and thyroid issues run in my family but how is the T4 SO high?
I’m waiting to see an endocrinologist and also a cardiologist for suspected POTS. Any advice would be great at this stage 🙂
Written by
Carebear92
To view profiles and participate in discussions please or .
Was that Free T4. what’s the range? Ranges vary between labs so always need to interpret accurately.
By most ranges it is very high. Very high hyper can be caused by Graves and that often occurs suddenly, but there are other causes of hyper and sometimes it can be temporary.
Do you have hyper symptoms? anxiety, weight loss, insomnia?
TSH & FT4 isn’t sufficient. For full thyroid you need. TSH, FT4 & FT3 TPO & TGab. (TSI & TRab is Graves suspected). Folate, ferritin, B12 and Vit D?
Hiya, yes it’s free serum T4. I think the top range is 14.4? Which is why it feels extremely high. I do have symptoms, mainly irritability, lightheadedness, heart racing, weakness and tiredness. I’ve lost my appetite slightly but also lost 5kg in the past 4 weeks. I’m having antibodies tested tomorrow but I wasn’t really sure what that means.
t4 can go high quickly if thyroid is being attacked by immune system . for 2 different reasons : a) Hashimoto's Disease ~ in the early stages of developing autoimmune hypothyroidism, when thyroid at attacked , it can dump a load of ready made T4 ( and T3 ) into the blood stream,,, this goes down eventually by itself as it is used up and then you eventually may go on to become hypothyroid, (as more thyroid tissue is damaged and can't produce enough T4 anymore) if that happens you usually need to take replacement thyroid hormones (Levothyroxine)
b) or..... the other autoimmune thyroid disease is Graves Disease. In this one the thyroid is stimulated to keep producing more and more T4 ( and T3) by some antibodies that act like just like TSH.. (they keep stimulating thyroid to make more T4 /T3 even though TSH is low)
in this case they use anti-thyroid drugs to stop the thyroid producing so much T4/T3 and these keep T4/T3 levels under control until eventually the antibodies reduce and thyroid calms down again and hopefully the Graves goes into remission and you don't need anti-thyroid drugs anymore .
There are other potential causes of high T4/T3 levels that are not Graves or Hashimoto's... eg 'hot' nodules on thyroid producing T4/T3 by them selves,.... or acute thyroiditis ...also there are some reports of high thyroid levels after either covid infection /or covid vaccination . But If you have family history of thyroid problems them autoimmune thyroid disease is probably the most likely culprit.
The job for GP/ Endo is to figure out the cause . The Endo can test for the antibodies that cause Graves ~ TRabThyroid Stimulating hormone Receptor antibodies.
The GP can check for the antibodies that are associated with Hashimoto's ~ TPOab Thyroid Peroxidase antibodies , but these don't rule out graves as some graves patients have then too/
An ultrasound scan of the thyroid can look for any nodules, and a different sort of scan can then tell it they are 'hot'.. GP's can sometimes get some of these tests done before seeing Endo.
GP's may also be able to prescribe antithyroid drugs with instruction from Endo to reduce production of 4/T3 .... or prescribe something (propanolol?) to help with heart symptoms in the meantime while the cause is being investigated .
The very high T4 (and presumably also high T3) is enough to cause the fast heart rate symptoms you had.
It's pretty shocking that the hospital failed to mention an fT4 of that level as the cause of your high heart rate .. was that blood test done at the hospital ?
I was asked about Graves’ disease in my family so I think that’s what my GP thinks it is. Having more blood tests tomorrow. I am apparently waiting for advice from the endocrinologist that my GP has requested but I don’t know what that means? I have been given propranolol in the mean time and they’re helping. The blood test was done at the hospital yes, my GP is fuming and we have both submitted a complaint. I was extremely unwell after I left the hospital for a few days and still not feeling too well now.
I’ll request the vitamin tests! Would make sense for me tbh I’ve eliminated gluten for IBS in the past and struggled 😂 my hypermobility isn’t EDS though so I’m not sure if it would be that
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
thyroid t4 tests shortage? 
Thyroid function tests 
Confused by thyroid test results
Thyroid test results+ pregnant 
Thyroid blood test results 
