You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Investigation of choice of hyper-prolactinemia- and explain in detail?
Basal, fasting morning prolactin(PRL) levels (normally <20 mg/L) should be measured to assess hypersecretion in hyperprolactinemia. In non-pregnant and non-lactating patients, monomeric prolactin concentrations of 500-1000 mU/L are likely to be induced by stress or drugs, and a repeat measurement is indicated. Levels between 1000 and 5000 mU/L are likely to be due to either drugs, a microprolactinoma or 'disconnection' hyperprolactinaemia. Levels above 5000 mU/L are highly suggestive of a macroprolactinoma. Reference : page 791 Davidson's Principles and practice of Medicine 22nd edition