This condition affects more women than men, and can occur quite early on in life. It affects circulation by causing the blood supply to the hands and feet (and sometimes other areas such as the nose) to be interrupted, upon which those areas turn white then blue as the oxygen supply runs out, and then red as the blood supply is finally resumed. During the white and blue stage, cold and numbness are the primary features, but the return of feeling can be exquisitely painful.
Blood vessels naturally contract in colder weather to reduce the amount of warm blood that is exposed to the cooler surface. The main cause of Raynaud's is these vessels becoming oversensitive and contracting too fiercely when exposed to a drop in temperature. This prevents blood from reaching the far-flung regions of hands and feet.
Raynaud’s syndrome can also be caused by a secondary condition, usually an autoimmune disorder. Conditions responsible are wide ranging and include rheumatoid arthritis and lupus. For this reason it is always a good idea to consult your doctor if you have Raynaud's to identify any underlying condition.
It is extremely important to avoid sudden temperature changes, and to make every effort to dress warmly enough. Hats, gloves, scarves and warm footwear should be worn even when other, warmer blooded creatures are scampering around in scanty clothing.
Smoking will worsen this condition, as it affects the blood flow through the smaller blood vessels. Stress has a similarly adverse effect on blood flow, so nutrients that support the nervous system, such as vitamin B and magnesium, may be helpful supplements.
Check your blood pressure with your doctor, as low blood pressure (below 120/75) can be a contributory factor. It is also a known side effect of some drugs such as beta-blockers. A sedentary lifestyle will exacerbate symptoms, whereas regular exercise (even if only gentle) will improve blood flow around the body and boost low blood pressure.
Eat warming foods in cold weather, adding plenty of stimulating spices such as ginger and pepper. Fish oils and garlic will help blood flow, and can be both used in the diet and taken as supplements. If the condition has occurred whilst working with vibratory tools such as power drills, then consult your doctor and, if the tools are associated with your work, then talk to the health and safety representative.