Assay interference

Breastfeeding

Exercise

Familial (mutant prolactin receptor)

Idiopathic

Macroprolactin ("big prolactin")

Nipple stimulation

Neonatal

Pregnancy

Sleep (REM phase)

Stress (trauma, surgery)

Amoxapine

Amphetamines

Anesthetic agents

Antipsychotics (conventional and atypical)

Androgens

Butyrophenones

Cimetidine (not famotidine or nizatidine)

Cocaine use or withdrawal

Domperidone

Estrogens

Hydroxyzine

Licorice (real)

Locaserin

MAO inhibitors

Methyldopa

Metoclopramide

Opioids

Nicotine

Phenothiazines

Protease inhibitors

Progestins

Reserpine

SSRIs

Tricyclic antidepressants

Verapamil

Acromegaly

Adrenal insufficiency

Chronic chest wall stimulation (thoracotomy, augmentation or reduction mammoplasty, mastectomy, herpes zoster, chest acupuncture, nipple rings, etc)

Hypophysitis

Hypothalamic or pituitary stalk damage

Hypothyroidism

Liver disease

Multiple sclerosis

Optic neuromyelitis

Prolactin-secreting tumors

Pseudocyesis (false pregnancy)

Renal insufficiency (especially with zinc deficiency)

Spinal cord lesions

SLE