A review of current knowledge on the pathophysiological aspects of peripheral circulatory derangements in the hand-arm vibration syndrome is presented. Hemodynamic measurements indicate that the primary factor in vibration-induced white finger is an increase in peripheral resistance of finger circulation, present after local and general cooling. The reason for this increase is not known, but it is postulated that there is an excess affinity for the efferent receptors of vasoactive substances and that this affinity is potentiated during local cooling of the digits.