Commonest histological finding in benign hypertension is -
Hyaline arteriosclerosis consists of homogeneous pink hyaline thickening of the wall of the arterioles with loss of underlying structural detail.
Encountered frequently in elderly patients whether normotensive or hypertensive, hyaline arteriosclerosis is more generalized and more severe in patients with hypertension.
It is also common in diabetes as a part of the characteristic microangiopathy.

Pathogenesis

The lesion reflects leakage of plasma components across vascular endothelium and excessive extracellular matrix production by smooth muscle cells secondary to the chronic hemodynamic stress of hypertension or a metabolic stress in diabetes that accentuates endothelial cell injury.

Also, know
Hyperplastic arteriosclerosis

It is characteristic of malignant hypertension.
There is concentrically laminated thickening of arteriolar wall → onion thickening.
There is mucinous intimal thickening and fibrous intimal thickening.
There may be accompanied fibrinoid deposited with necrosis of the vessel wall → fibrinoid necrosis.
Proliferative endarteritis
Necrotizing arteriolitis
Hyaline arteriosclerosis
Cystic medial necrosis