Renovascular hypertension, or renal parenchymal hypertension, is a type of secondary hypertension brought on by anomalies in the kidney's functional tissue, the renal parenchyma. The renal arteries or their branches constrict or get blocked, resulting in decreased blood flow to the kidneys. This decreased blood flow sets off a series of actions that culminate in hypertension. There are various causes for the renal arteries to narrow. Atherosclerosis, a disorder where plaque accumulation in the arteries decreases blood flow, is a frequent cause. Additional causes include renal artery stenosis, which is the narrowing of the renal arteries as a result of many circumstances, and fibromuscular dysplasia, a disorder in which the artery walls thicken and narrow.The kidneys interpret a reduction in blood flow to the kidneys as low blood pressure. Activating the renin-angiotensin-aldosterone system (RAAS), they respond by releasing hormones such renin. The body's fluid balance and blood pressure are controlled by this system. But in renal parenchymal hypertension, the kidneys retain more water and salt as a result of the RAAS activation, which raises blood pressure by increasing blood volume. Renal parenchymal hypertension can manifest itself in a variety of ways clinically. Patients may exhibit headaches, lightheadedness, and blurred vision as signs of hypertension. Severe instances may result in problems like renal failure, heart failure, or stroke.A combination of the patient's medical history, physical examination, and diagnostic testing is frequently used to diagnose renal parenchymal hypertension. Imaging tests that visualize the renal arteries and detect any narrowing or blockages include Doppler ultrasonography, magnetic resonance angiography (MRA), and computed tomography angiography (CTA).Reduction of blood pressure and enhancement of renal blood flow are the goals of treatment for renal parenchymal hypertension. This could entail changing one's way of living to adopt a healthier diet, engage in regular exercise, and give up smoking. ACE inhibitors, angiotensin II receptor blockers (ARBs), and diuretics are a few examples of medications that may be used to lower blood pressure and lessen RAAS activation. To restore blood flow, angioplasty with stenting or surgical revascularization may be required in cases when there is a severe blockage in the renal arteries.
