Galactorrhea can be defined as inappropriate lactation or milk-like discharge from the breast (in the absence of pregnancy or postpartum state).

• Milky discharge from nipples, usually occurring bilaterally.
• Evidence of chest wall irritation from ill-fitting clothing, herpes zoster, or atopic dermatitis may be present.
• Visual field defects (bitemporal hemianopsia) may be present with prolactinomas, particularly if large, such as macroadenomas.
• Headaches may also occur in cases of large pituitary adenomas.
• Evidence of acromegaly, Cushing syndrome, or hypothyroidism when galactorrhea is caused by these disorders.

• Medications (phenothiazines, metoclopramide, selective serotonin reuptake inhibitors, anxiolytics, buspirone, risperidone, atenolol, valproic acid, conjugated estrogen and medroxyprogesterone, methyldopa, verapamil, H₂ receptor blockers [cimetidine], octreotide, danazol, tricyclic antidepressants, isoniazid, amphetamine, reserpine, opiates, sumatriptan, rimantadine, oral contraceptive formulations): After infancy, galactorrhea is often medication induced¹
• Pituitary tumors (prolactinomas, craniopharyngiomas)
• Hypothyroidism (diminished feedback inhibition increases thyroid-releasing hormone [TRH], which increases prolactin)
• Breast stimulation: Prolonged suckling or during sexual intercourse
• Chest wall irritation from ill-fitting clothing, herpes zoster, atopic dermatitis, burns
• Breast surgery
• Chronic renal failure (decreased prolactin clearance)
• Cushing syndrome
• Herbs (e.g., fennel, red clover, anise, red raspberry, marshmallow)
• Cocaine
• Cannabis
• Spinal cord surgery or injury, or tumors
• Severe gastroesophageal reflux disease, esophagitis (stimulation of thoracic nerves by the cervical and thoracic ganglia)
• Neonatal (“witch’s milk” produced by 2% to 5% of neonates because of precipitous drop in maternal estrogen and progesterone postdelivery)
• Cancer: Lymphomas, Hodgkin disease, bronchogenic carcinoma, renal adenocarcinomas
• Sarcoidosis and other infiltrative disorders
• Tuberculosis affecting pituitary gland
• Pituitary stalk resection
• Multiple sclerosis
• Empty sella syndrome
• Acromegaly
• Increased stress, including major trauma
• Exercise
• Idiopathic, diagnosis of exclusion

• Intraductal papilloma
• Breast cancer
• Paget disease of breast
• Breast abscess

• Complete history focusing on menstrual irregularity, infertility, previous pregnancies, duration of galactorrhea, medications, visual complaints, fatigue. Age of onset is also significant (e.g., prolactinoma most common between ages 20 and 35 yr. Neonatal galactorrhea is usually secondary to transplacental transfer of maternal estrogen).
• Physical examination:
  1. Height, weight, vital signs
  2. Evidence of hirsutism, acne, obesity, visual field defects, goiter, neurologic deficits
  3. Breast examination for presence of nodules, evaluation of discharge (milky vs. serosanguineous versus purulent), bilateral or unilateral discharge
  4. Inspection of chest wall for lesions or concerning skin changes
• Laboratory testing and imaging studies (see “Laboratory Tests”)

• β-Human chorionic gonadotropin (HCG) test (positive in pregnancy)
• Prolactin level (elevated, often >200 ng/ml in prolactinoma but may occur at any prolactin level). Confirm with repeat fasting test (avoid exercise and breast stimulation)
• Thyroid-stimulating hormone (TSH) (elevated in hypothyroidism)
• Basic metabolic panel (BMP): Blood urea nitrogen, creatinine (elevated in renal failure), glucose (elevated in Cushing syndrome)
• Urinalysis (hematuria in renal cell carcinoma)
• Microscopic examination of nipple discharge (scant cellular material, numerous fat globules, can be seen without specific staining)

• MRI of brain if prolactin level is elevated, amenorrhea is present, or visual field defects are detected on physical examination.
• High-resolution computed tomography of brain with special coronal cuts through the pituitary region may be helpful in patients with contraindications to MRI; however, it may miss small lesions.
• If breast mass is identified or abnormal nipple discharge is encountered, recommend breast ultrasound (age <30 yr) or mammogram (age >30 yr).

Endocrine and neurosurgical consultation if prolactinoma is detected.

Galactorrhea (Patient Information)

Pituitary Adenoma (Related Key Topic)

Prolactinoma (Related Key Topic)