Diuresis is an increase in the production of urine — the kidneys excreting water at a faster rate than usual. It can be physiological, as after drinking a large volume of fluid, or pharmacological, driven by diuretic drugs prescribed for hypertension and heart failure; caffeine, alcohol, and high blood sugar all produce milder forms by different mechanisms. The body uses diuresis to correct fluid overload and to dump excess solutes, but sustained diuresis without replacement leads to dehydration and electrolyte disturbance — the reason diuretic therapy demands monitoring of potassium and kidney function. In clinical nutrition, fluid balance charts track diuresis against intake to judge whether a patient is gaining or losing water. The word names the output side of the body’s water economy, the complement to thirst on the input side.