Introduction

Diabetes is a general term for disorders characterised by polyuria. It usually refers to diabetes mellitus, a common chronic syndrome of impaired carbohydrate, protein, and fat metabolism owing to insufficient secretion of insulin and/or target-tissue insulin resistance. Complications of diabetes mellitus include both macrovascular (cardiovascular) and microvascular (retinopathy, nephropathy, or neuropathy) sequelae.

Diabetes insipidus (DI) is much less common and refers to disorders of vasopressin secretion (central DI) or action (nephrogenic DI), resulting in urinary concentrating abnormality.