In diagnostic nuclear medicine, a radiopharmaceutical is administered to the patient. A radiopharmaceutical is a substance that contains a radioactive atom and is suitable for use in the diagnosis or treatment of disease. Radiopharmaceuticals are formulated to deliver the radioactive atoms to particular parts of the body. In diagnostic nuclear medicine, radiation emitted by the radioactive atom is detected by a camera, providing information related to the function, position, size, borders and shape of the organ in question. In many cases, nuclear medicine provides important clinical information that is not provided by other imaging modalities. In therapeutic nuclear medicine, emitted radiation can kill cells that have abnormally high metabolic activity. This is the best available treatment in cats for a common hormonal disease called hyperthyroidism. Nuclear medicine patients do not experience pain from their procedures, nor do they experience short-term (deterministic) side effects of radiation exposure.