hypothyroidism thyroid gland

thyroid gland hypothyroidism hyperthyroidism vector goiter throat cancer disease thyroiditis hashimoto graves endocrine endocrinologist illustration hormone hyperthyroid anatomy medical endocrinology parathyroid hypothyroid symptoms disorder iodine loss test awareness deficiency overactive sick treatment human function unhealthy therapy neck symptom thyroxine underactive medicine healthy t3 t4 triiodothyronine hormonal organ system metabolism doctor