My 16 Year Old Daughter Is Being Sent To An

My 16 year old daughter is being sent to an endocrinologist after three lab tests showing consistently abnormal thyroid levels. The last 2 were done in 7/27/2015 with results of T3 2.5 pg/ml and thyroid peroxidase antibodies 30 IU/mL. They were done again 12/24/2015 with results of T3 2.8 and thyroid peroxidase antibodies 22. She had weight loss of about 30 pounds. In the last year she has had difficulty maintaining and gaining weight, hair loss, fatigue. What could these results mean?