Hyperprolactinemia ( galactorrhea , amenorrhea, loss of libido , impotence , infertility ).
First test >>> exclude pregnancy
Next step >> check list of medications ( antidopaminergic drugs like antiemetic or antipsychotic )
Next step >>> check thyroid state .A low T4 and high TSH indicates hypothyroid state as a cause of hyperprolactinemia ( usually less than 1000) .
Next check visual fields .If visual fields affected ( bitemporal hemianopia) = macroprolactinoma ( prolactin usually above 5000)) or non functioning adenoma ( around 1000) >>>> MRI ( tumour above 1 cm ) .
No visual field defect and level around 5000 ( usually around 3000)>>> micropolactinoma is more likely .