Raynaud's phenomenon: causes

 COLD HAND:
Cryoglobulins/ Cryofibrinogens
Obstruction/ Occupational
Lupus erythematosus, other connective tissue disease
Diabetes mellitus/ Drugs
Hematologic problems (polycythemia, leukemia, etc)
Arterial problems (atherosclerosis)
Neurologic problems (vascular tone)
Disease of unknown origin (idiopathic