Aliskiren is primarily used in the treatment of hypertension, or high blood pressure. It works by inhibiting renin, an enzyme that plays a crucial role in the regulation of blood pressure. By blocking renin, aliskiren reduces the production of angiotensin I and II, leading to the relaxation of blood vessels and a decrease in blood pressure. This makes it effective in managing hypertension, either as a standalone therapy or in combination with other antihypertensive medications. Additionally, it is sometimes considered for patients who do not respond well to other blood pressure-lowering drugs or those with specific conditions like heart failure or chronic kidney disease, where renin inhibition may provide additional benefits. However, its use is carefully monitored due to potential risks, such as hyperkalemia or renal impairment, especially in certain patient populations.