Final answer:
If a patient with hyperthyroidism has low RAI uptake, the next step is to measure the TSH level, which confirms the diagnosis of primary hyperthyroidism. The TSH level helps determine the appropriate treatment approach.
Step-by-step explanation:
If a patient has hyperthyroidism with low Radioactive Iodine (RAI) uptake, the next step is to measure the thyroid stimulating hormone (TSH) level. TSH is produced by the pituitary gland and stimulates the thyroid gland to produce thyroid hormones. A low TSH level indicates that the problem lies in the thyroid gland itself, rather than in the pituitary gland. This finding confirms the diagnosis of primary hyperthyroidism.
Furthermore, the result of the TSH level measurement is important in determining the appropriate treatment approach. In primary hyperthyroidism, the most common cause is Graves' disease. Treatment options may include medications, radioactive iodine therapy, or surgery, and the choice of treatment depends on a variety of factors, including the patient's preference.