Where do thiazide diuretics primarily act in the nephron?

Thiazide diuretics primarily act in the distal convoluted tubule of the nephron. This segment of the nephron is responsible for reabsorbing sodium and water, and thiazide diuretics inhibit the sodium-chloride symporter in this area. By blocking this transporter, thiazide diuretics increase the excretion of sodium and water, effectively lowering blood volume and blood pressure.

This mechanism is crucial for their role in managing hypertension and can also help in treating conditions like heart failure. The action at the distal convoluted tubule distinguishes thiazide diuretics from other types of diuretics that work in different parts of the nephron, such as loop diuretics that act in the loop of Henle or potassium-sparing diuretics that affect the collecting duct.