ObjectiveEating disorders are a common clinical problem among young women in Asian countries. The aim of this study is to determine the medical effects of anorexia nervosa (AN) in the Korean population.MethodsWe comprehensively investigated medical complications including haemodynamic, haematologic, endocrine, and bone density abnormalities in 67 Korean women with AN, together with 194 healthy Korean women of comparable age with a cross-sectional design.ResultsIn AN, 36.9% were anaemic, 50.8% were leukopenic, 35.5% were hypoproteinemic, 7.9% were hypokalemic, 9.5% had increased alanine aminotransferase, 6.3% were hyperbilirubinemia, 14.5% were hypercholesterolemia, 14.8% had decreased triiodothyronine. Osteopenia at any one site was identified in 43.3% and an additional 13.4% had osteoporosis. The lowest-ever body mass index was the main determinant of bone mineral density.ConclusionOur data in Korean patients with AN show high frequencies of laboratory abnormalities for medical complications. This study emphasizes the importance of recognizing AN as a medical risk in young Korean women.