Hashimoto's disease is not the same as hypothyroidism. Hashimoto's disease is an autoimmune condition in which there is inflammation of the thyroid gland. It is also referred to as chronic lymphocytic thyroiditis. In this condition, the immune system attacks and destroys thyroid tissue. During this destructive phase, an individual can experience transient hyperthyroidism where the thyroid cells release thyroid hormone in an unregulated manner. Hyperthyroidism is when the gland is overactive and produces more thyroid hormones than are needed. This phase, if it were to occur, is referred to as hashitoxicosis. Once enough tissue has been destroyed, hypothyroidism will occur. Blood work most likley with detect postivie antibodies and abnormal thyroid hormone values. If an ultrasound is obtained, the thyroid gland maybe enlarged, show increased blood flow, and appear to have pseudonodules giving the gland a giraffe-like pattern. Overtime, if the gland has been destroyed it will appear atrophic or small with decreased blood flow. Of note, an ultrasound is not required to make the diagnosis nor needed for routine management.