underactive thyroid
"I had only recently started thyroid medication. Just 25mg of Levothyroxine.(My TSH was 5.43, I was told borderline)  I took it for about 9 days.

Then I felt a bit out of breath,  I had a sort of pressure on my chest, sweating, trembling, palpitations and diarrhoea.

I had a paramedic check me over and he suggested I go to A&E to be checked out. So an Ambulance was called.

Anyway I had bloods taken and ECG's etc done and fortunately all was ok. But they think it  was the Levothyroxine that  had caused this. I have now stopped taking it."