Renal artery stenosis is most commonly caused by the development of atherosclerotic plaque in the renal arteries (termed atherosclerotic renal artery stenosis). Less frequently, it is caused by fibromuscular dysplasia.

Unilateral Renal artery stenosis has two major causes:

1) Atherosclerosis^[1]: Most common cause seen in almost 60-90 percent of the cases associated with renal artery stenosis. Atherosclerosis mostly affects men over the age of 45 years and mainly involves the proximal part of the main renal artery. Although this condition is also commonly seen as an isolated lesion even in patients not having the underlying atherosclerotic disease. The risk factors associated with atherosclerosis are dyslipidemia, cigarette smoking, virus infection, immune damage, and elevated concentrations of homocysteine.

2) Fibromuscular dysplasia^[2][3]: This is responsible for causing renal artery stenosis in the remaining 10-30 percent of cases. This is most commonly seen in women under the age of 50 years and mainly involves middle and distal renal arteries and typically involves the middle and distal main renal artery or the intrarenal branches.

3) In, Less than 10 percent of the patient population other less common factors play a role like

– Thromboembolic disease

– Aortic aneurysms

– Takayasu arteritis

– Polyarteritis nodosa

– Retroperitoneal fibrosis.