label: Reduced radioactive iodine uptake
label_lc: reduced radioactive iodine uptake
description: "A decreased amount of uptake on the radioactive iodine uptake (RAIU) test, which utilizes a radioisotope of iodine to measure how much iodine the thyroid gland absorbs from the blood. The radioactive marker is measured 4-6 hours and in some cases also 24 hours after administration of the radioactive marker."