Symptomatic macromastia (enlarged breasts) is a syndrome of persistent headache, neck and shoulder pain, thoracic kyphosis, painful shoulder grooving from bra straps, inframammary rash, backache, and upper extremity paresthesias. Up to 89% of the 100,000 US women undergoing breast reduction surgery (reduction mammoplasty) annually report headache preoperatively with many endorsing postoperative headache improvement. Headache is one insurance indication to cover surgical reduction, and peak prevalence of migraine matches the average age of women with macromastia at time of surgery. Little is known about the influence of macromastia on headache. The goal of our narrative review is to understand the evidence for and potential mechanisms underlying macromastia-related headache. A literature search was performed in PubMed Medline using concepts "breast hypertrophy," "macromastia," "headache," "migraine," "breast reduction," and "reduction mammoplasty" excluding limits on age, language, publication date, or study type. Supplemental literature searches were performed to provide a comprehensive understanding of potential mechanisms underlying macromastia-related headache. We identified 25 studies describing macromastia-associated headache in the setting of reduction mammoplasty, with 23 original research studies (retrospective, n = 12, prospective, n = 11) totaling 3,799 patients, 1 systematic review, and 1 meta-analysis. Most (24/25) were published in Plastic Surgery, one in Internal Medicine, and none in Neurology. Wide ranges were identified for preoperative headache prevalence (2%-89%) and postoperative headache improvement (34%-100%). Studies described headache as "myofascial" or "tension-type" without detailing headache definitions, chronicity, headache screening method, or neurologic examination. Potential pathophysiologic mechanisms of macromastia-associated headache include structural, mechanical, psychosocial, and hormonal. No studies on macromastia-associated headache and reduction mammoplasty are published in Neurology. This important women's health topic remains unexplored in fields outside Plastic Surgery. Many questions remain unanswered that are important for neurologists to understand, including which headache type(s) women with macromastia experience and which headache type(s) respond to surgical intervention.