Diabetes Insipidus I: Introduction

Diabetes Insipidus, or DI, is a syndrome that features excessive urination, known as polyuria, and intense thirst, called polydipsia.

It develops either due to a deficiency of the antidiuretic hormone ADH or because the kidneys cannot effectively respond to ADH.

In the absence of ADH, the kidneys excrete 10 to 20 liters of dilute urine daily, compared to the normal 1 to 2 liters of concentrated urine.

Clinically, DI presents with frequent urination even during dehydration, marked nocturia in adults, and enuresis in children.

Thirst is a prominent symptom, and when fluid intake does not match urinary loss, dehydration can develop.

There are three main types of DI.

Central DI results from reduced ADH production, often due to brain injury or intracranial tumors.

Nephrogenic DI results from the kidneys' inability to respond appropriately to ADH, often associated with chronic kidney disease or certain drugs like lithium carbonate.

Gestational DI can develop during pregnancy due to an excess production of placental vasopressinase, which breaks down ADH.