The etiology of carotid abnormalities is both congenital than acquired. The aim of this study was to clarify the role of aging and atherosclerosis in the acquired cases, and the role of these abnormalities in hemodynamic alterations and neurologic symptoms. Over a 1-year period the authors studied all the subjects undergoing carotid examination by continuous-wave and color-coded Doppler sonography at an Angiology Unit. They evaluated neurologic symptoms; risk factors for atherosclerosis; number, sites, and kinds of carotid abnormalities; atherosclerotic lesions; stenosis; hemodynamic alterations of the carotid; and other localizations of atherosclerotic diseases. There were 469 subjects: 272 (58%) with abnormalities (group 1) and 197 (42%) without abnormalities (group 2). The total number of abnormalities was 479 (104 tortuosities, 262 kinkings, and 113 coilings). The abnormalities were more prevalent in the elderly (P<0.001) and in women (P<0.001). In group 1 they found significant prevalences of hyperlipemia (P<0.001), hypertension (P<0.01), chronic cigarette smoking (P<0.01), and ischemic heart disease (P<0.05). Carotid atherosclerotic lesions were more prevalent in group 1 than in group 2 (P<0.001); among the patients with atherosclerotic carotid lesions, those in group 1 were older than those in group 2 (P<0.001). Tortuosity seemed to be associated with fewer hemodynamic alterations. The authors conclude that atherosclerosis, hypertension, and aging may play an important role in producing carotid abnormalities. The aging seemed more important than atherosclerosis. Only a prospective study of patients with carotid abnormalities and no atherosclerotic lesion will clarify the role of hemodynamics and neurologic symptomatology.