Postmoem studies of a man shows onion skin thickening of aeriolar wall which is characteristic of:

Hyperplastic aeriosclerosis occurs in severe (malignant hypeension); vessels exhibit 'onion-skin lesions', characterized by concentric, laminated thickening of the walls and luminal narrowing. The laminations consist of smooth muscle cells with thickened, reduplicated basement membranes; in malignant hypeension they are accompanied by fibrinoid deposits and vessel wall necrosis (necrotizing aeriolitis), paicularly in kidney. Ref: Robbins & Cotran Pathologic Basis of Disease, By Vinay Kumar, Abul K. Abbas, Nelson Fausto, Jon C. Aster, 2009, Chapter 11.