Does anyone here have any information on hyperthyroidism? I've been dealing with symptoms for over a year, and thyroid issues run rampant in both sides of my family, yet my doctor refuses to refer me to an endocrinologist as my lab numbers are (barely) within the range set by the testing lab.

For over a year now my TSH has been between 0.3 and 0.5, I lost 30lbs in a month and can't gain any back regardless of what I eat, my heart pounds in my chest head and neck, I'm shaky, freezing cold and have a physical sensation of fear 24/7. Also my vision goes double.

Regardless of what my doctor thinks I've concluded that the problem is almost certainly my thyroid (and probably graves disease). Things I've tried that didn't seem to help include: tons of cardio, yoga, eating a super clean diet focused on high protein and low carbs/grains/no sugar, CBT therapy for anxiety, and a large variety of supplements and vitamins.

The only thing I've done that has made a difference so far is taking 2 grams of an amino acid called l-carnitine every day. Since I've started this my heart palpitations have decreased noticeably and I'm less shaky most of the time

Does anyone here have any information about hyperthyroidism? What causes it and how can it be managed without prescription medication? It's generally considered an 'autoimmune' disorder, but nobody seems to know what causes these disorders in the first place...