Vibration, the Law and Trigger Time WA Management Hand Arm Vibration Syndrome HAVS Vibration White Finger Raynaud's phenomenon is a condition where small blood vessels in the fingers and toes suddenly narrow in response to cold or stress. This causes the classic color changes: white (reduced blood flow), Vibration White Finger (VWF) and Hand Arm Vibration Syndrome (HAVS) Venus Legal Hand Arm Vibration Syndrome