Hi, I was wondering if anyone can help me understand whats going on with my thyroid because I am stumped. I was born with underactive thyroid and it was under control until two years ago-I then put on 3 and a half stone in 3 months, was constantly tired and developed a goitre a year ago, which is painful/throbs amongst other symptoms. In the last two weeks I have become incredibly cold/shivery with trembles and painful chest/tight chest/heart palpitations with upper back pain, and heavy chest/difficulty breathing/laboured breathing. I went to the Drs for bloods and was told today my TSH is 17. something yet I am on 200mg daily. I have now been upped to 225mg daily which I am concerned about because of my chest pain/heart palpitations. I am booked in for ECG next week, and scan on throat. Dr said my antibodies are within range. I dont understand why my TSH is so high when I am on such a high dose but my Dr said my T4 was ok (dont know about free T3 at this point). My kidney function isnt great(last time checked my EGFR dropped 11 in one week to 73) and need the loo constantly. Can anyone shed any light on what may be going on?