Having felt really ill since Monday (collapsing, palps, feeling faint and weak), been to A&E twice, being told all my tests (they didn't do thyroid tests) are normal and that I have chronic fatigue syndrome (which I had about 10 years ago), where do I go from here? My previous post gives details of dosage, but still on 5 mcgs T3 plus levo and have not been able to increase it without unpleasant symptoms. Despite collapsing, fatigue and brain fog seem to have disappeared. I am arranging to have private thyroid and B12 tests (some symptoms of B12 deficiency, including sore tongue and tingly feet and hands) via Blue Horizon today and am booking in to a reputable doctor. Do I stop taking the T3 for a while, increase the levo and see what happens. I don't want to get the horrible fatigue/malaise symptoms I had on leve alone. Is T3 for me?