Hello, I have a history of hyperthyroidism and graves disease. I have been really weak, tired, forgetful, nauseous and i have fainted once today. i don t have a fever but i do have low blood pressure 82/50 64 pulse last time i checked it today. i am 25 year old at 5 feet 2 ounces and 94 pounds my body mass is about 17.4. no matter how much i eat i cant gain weight. I m feeling sicker and sicker everyday. what do i do i cant get better. i also have a headache that wont go away!