Hand Arm Vibration Syndrome (HAVS) 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, the Law and Trigger Time WA Management Vibration white finger (VWF) (Koon, 2019). Download Scientific Diagram What Causes Hand Arm Vibration Syndrome and How to Prevent It Hovair