Lactation headache--a new form of headache?

The case of a 26-year-old woman suffering from brief attacks of headache occurring on every occasion of nursing is described. Pulse rate and blood pressure are normal during the attacks and serum prolactin responds normally to nursing. Plasma vasopressin increases before each headache attack. Propranolol does not prevent the headache, which disappears only after lactation has ceased. Possible pathophysiological mechanisms related to suckling are discussed.