To report a case of young male patient who had obvious changes in eating habits, weight, endocrine hormones, and hematological parameters after subarachnoid hemorrhage and to review the related literature and summarize the clinical features of anorexia nervosa (AN) in male patients in order to provide the reference for its clinical diagnosis and treatment.

A retrospective analysis of AN was performed by reviewing the related literature to discuss its clinical characteristics, laboratory examinations, psychological evaluation, treatment, and prognosis in a young male patient.

The diagnosis of AN was made in this patient according to the characteristics of the history, laboratory findings, imaging examinations, and psychological evaluation after excluding other diseases that may cause weight loss, such as tuberculosis, tumor, and digestive tract lesions. The patient was given complex amino acids, fat milk, diet therapy, and psychological counseling, after which his body weight gradually increased and his endocrine hormones and blood test results improved. No mental drugs were administered. During the regular follow-up, the patient′s condition improved.

AN in young males is rare and easily misdiagnosed. If AN is suspected, psychologists should be invited to make a multidisciplinary diagnosis timely. AN has a poor prognosis. Rebuilding diet habit, psychiatric behavior intervention, and family cooperation are more effective than single nutritional support therapy. Body weight is an independent index to indicate the prognosis and recovery of AN. Therefore, monitoring the change of body weight and adjusting therapeutic strategy based on body weight is an effective measure to treat AN patients.