This chapter gives a brief overview of the eating disorders (EDs) such as anorexia nervosa (AN), Bulimia nervosa (BN), and eating disorder not otherwise specified (EDNOS). It discusses recognition of EDs and commonly associated medical complications and their management in the acute setting. Patients with EDs are often quite reluctant to disclose their illness to healthcare providers and may present to the emergency department with vague non-specific complaints rather than complaints directly attributable to their ED. Identification and proper management of these patients requires the healthcare provider to maintain a high index of suspicion for these illnesses and to readily recognize signs and symptoms consistent with ED pathology. Common presenting complaints include headache, mood changes, sore throat, dizziness/syncope, palpitations, fatigue/generalized weakness, sports-related or overuse injuries, and gastrointestinal (GI) complaints such as indigestion, abdominal pain, bloating, constipation, and hematemesis. The chapter also provides suggestions for definitive, long-term treatment referral.