Diuretics are a class of medications that promote the excretion of water and electrolytes from the body through increased urine production. They are commonly used to treat conditions such as hypertension, heart failure, and edema by reducing fluid overload. By acting on the kidneys, diuretics help lower blood pressure and decrease swelling, improving overall fluid balance. There are different types of diuretics, including thiazide, loop, and potassium-sparing diuretics, each with specific mechanisms and uses.