Secreted from the pituitary, but also a stress hormone (can be used to distinguish pseudo seizures from epileptic seizures). So can go up to 1000 in healthy people. Always worth repeating a high result at least 24hrs hours later, after a 20 minute rest.
Important because of prolactinomas, which can cause:
- delayed puberty
- space occupying lesion effects – headaches, visual field defects
Any lesion in the vicinity of the pituitary may also cause raised prolactin so not specific.
In children, high levels can be due to presence of macroprotein isoforms, which are not considered pathological – lab can check.