Bulimia nervosa is an eating disorder characterized by repeated binge eating with compensatory behaviours. This Primer discusses the epidemiology, pathophysiology, diagnosis and treatment of bulimia nervosa.

Eosinophilic gastrointestinal diseases are immune-mediated, inflammatory disorders of the gastrointestinal tract, defined by pathological mucosal eosinophilic infiltration. In this Primer, Lenti et al. summarize the epidemiology and pathophysiology of this group of diseases, discuss their diagnosis and management, and highlight patients’ quality of life and future research areas.

The thalassaemia syndromes are genetic disorders that affect the production of normal haemoglobin. In this Primer, Piel and colleagues describe the epidemiology of the thalassaemia syndromes; discuss their mechanisms, diagnosis and management; and highlight patients’ quality of life and questions for future research.

Accidental hypothermia, in particular its moderate and severe forms, is a medical emergency owing to the associated risks of arrhythmias, organ dysfunction and cardiac arrest. In this Primer, Darocha et al. describe the epidemiology and mechanisms of this condition, and discuss its diagnosis, management and effects on quality of life, and future research directions.

In this Primer, Vaidya and colleagues review the epidemiology, pathophysiology, diagnosis, management and quality of life of patients with primary aldosteronism, an important cause of hypertension resulting from excessive aldosterone production by one or both adrenal glands.

Chronic graft-versus-host disease (cGVHD) is a major complication of allogeneic haematopoietic cell transplantation. In this Primer, Ye and colleagues describe the epidemiology of cGVHD, discuss its mechanisms, diagnosis and management, and summarize important questions regarding the quality of life of patients and future research.