What is likely the cause is that skin has nerve fibers that sense temperature, and the fibers differ among various people. The thermoregulatory vessels may be damaged in some people, thus causing the Raynaud’s syndrome.
If You Have Raynaud's
Those who are bothered by the symptoms of Raynaud’s phenomenon will have to undergo tests that will determine whether they have the primary or secondary form of the disease. The tests used to take observations of several years, but now nail fold capillary tests and blood tests, coupled with the patient's age, can predictably determine Raynaud’s phenomenon.
In one prominent Canadian study that was later published in the medical journal Arthritis & Rheumatism, 600 people believed to have a connective tissue disease or scleroderma were followed for 15 years. That research was the basis for the nail folds discovery. Those who have nail fold abnormalities went on to develop a disease like lupus or scleroderma. Those who had normal nail folds but still had Raynaud’s phenomenon were primary patients and did not develop the secondary diseases.
Most people who have primary Raynaud’s phenomenon and no secondary diseases will just live with the condition. Some may treat the disorder with drugs, most of them with off-label uses of other drugs like nifedipine (Procardia), which is used for blood pressure control. These medications can help reduce the number and severity of Raynaud’s phenomenon attacks, and thus are used sometimes in patients who are bothered by a severe form.
In an interesting recent development, drugs like Viagra and Cialis, which are used for erectile dysfunction, have been found to have uses for patients with secondary Raynaud’s phenomenon experiences. And some have even found benefit from Botox injections.