Hello dear Understand your concern. I think It may be due to allergy to cold or raynaud s phenomona. It is due to constriction of blood vessels of hand that lead to reduced blood in that area and when oxygen also depleted it converted in to the blue clour that called cynosis. Yes you should consult the MD doctor more investigation. Exact cause of raynaud phenomena is not known but it may be associated with following diseases and factor: Smoking and caffeine use Connective tissue disorder: SLE, systemic sclerosis, vasculitis, Rhematoid arthritis, peripheral arterial disease, CHF. Consult the doctor and do the following tests: CBC, ESR, CRP, Cryglobulin Kidney and liver function test Colour doppler USG of hand and feets to know the vessels blood flow Thyroid function test Urine routine and microscopic examination Antibodies like: ANA, RA factor, Anti Ds DNA, Anti CRP Xray of hand and feet Doctor may provide following treatment: Diltiazen, prazosinee, losartan and statin Hope this may help you Best regards Dr. Sagar