MODEL RELEASED. Hypothyroidism, conceptual composite image. At centre, a woman is holding her painful neck. At left is a nuclear medicine scientist, responsible for taking gamma camera scans (scintigrams), such as the one at upper right. This shows underactivity in the left (right in image) lobe of the gland (purple). The results below the scan confirm this: the uptake of a radioactive iodine tracer 15 minutes post- injection was 0.83% for the right lobe, but only 0.56% for the left lobe. Hypothyroidism is underactivity of the thyroid, a gland that produces hormones that regulate the metabolism. It can be treated with hormone pills (lower right).