Raynaud's phenomenon is an exaggerated vascular response to cold or stress manifested by skin colour changes at several locations, having three characteristic phases: pallor (white), cyanosis (blue) and rubor (red). When the cause is not known this phenomenon is termed primary Raynaud's phenomenon and secondary Raynaud's phenomenon when underlying disease is involved, autoimmune disease being the most frequent cause of the secondary form. Primary Raynaud's phenomenon has a good prognosis and can be treated medically without the need for specialist assessment, unlike secondary Raynaud's phenomenon which needs specialist assessment and treatment. A general practitioner needs to know the classification, the basis for treatment for signs and symptoms control and know when a patient requires specialist evaluation for treatment according to other diseases which may be present or coexist.