What are the symptoms? The key feature of Raynaud’s is colour changes associated with exposure to cold or any change in temperature. These changes occur most commonly in the hands, but may also affect the feet and occasionally other extremities, such as the nose or the tips of the ears. The hands of Raynaud’s patients turn white, then blue, then later red as the circulation improves. In severe Raynaud’s, there may be considerable pain, ulceration or gangrene. Raynaud’s can occur in children, although it is rare. The symptoms are the same as those of the adult disease. What are the causes? Although the precise cause of Raynaud’s is not known it appears to be due to excessive constriction of the blood vessel wall due to increased levels of normal stimuli that narrow blood vessels or deficiency of the factors that normally open them. In severe cases, blood vessels may become thickened or partially blocked. Recent studies suggest that there can be a genetic basis and Raynaud’s can run in families but this is complex and cannot yet be tested for in a routine way. How is it diagnosed? Raynaud’s is diagnosed usually by history of colour changes (white, blue, red) in the hands in response to cold and the condition can be confirmed by special tests that examine blood flow after cooling the hands or using medical charts with pictures of typical hands during a Raynaud’s attack. More important is the distinction between primary and secondary Raynaud’s and this requires blood tests and sometimes an examination of the blood vessels at the fingertip using a special magnifying lens or microscope. How is it treated? Treatments include avoiding cold exposure, avoiding cigarette smoking and using devices such as hand warmers. Many sufferers find certain vitamin or nutrient supplements helpful and some require prescription medication from their doctor. Current drugs used are mostly vasodilators that block spasm or open up narrowed blood vessels. Side effects such as headache can limit their use, but many find them beneficial. Inheritance patterns and prenatal diagnosis Inheritance patternsRaynaud’s can be hereditary but this is not due to a single gene rather a combination of genetic factors and so there is no simple test for this. Reassuringly the cases of Raynaud’s that are inherited are almost always primary Raynaud’s. Prenatal diagnosisNone. Is there support? Information and support in the UK for Raynaud’s phenomenon is provided by Scleroderma and Raynaud’s UK (see entry Scleroderma).