Oxytocin induced.... Lactation headache, an unusual form of headache during the lactation, is believed to be triggered by the release of oxytocin which induces let down of milk from breast, and cause a spasm of arterioles (small ateries) in brain in some breastfeeding women resulting in headache. No specific treatment has been established yet. Ibuprofen (advil, motrin) is safe to try to relieve the headache.
Can help yourself. Lactation or breastfeeding headaches can be caused most commonly by weaning too quickly, exhaustion, dehydration, poor diet, stress, thyroid changes and hormonal changes, estrogen and oxytocin (control of milk release). Try to relax, eat a well balanced diet, and drink plenty of fluids.