high TSH with normal T3 and T4 or slightly ncreased can happen in the beginning of the disease or if the patient is on throid replacement therapy so i recommend you to do FT3 and FT4 for that patient and to repeat the TSH again after 1 month also to do prolactin as both of them come from the posterior pituitary gland last thing is to do antithyroid antibodies to exclude autoimmune cause of hypothyroidism