Raynaud's phenomenon is classified theoretically into primary (idiopathic, cold-sensitive, often inherited), secondary (occurring in the setting of systemic autoimmune disease such as lupus or rheumatoid arthritis), and syndrome forms (triggered by identifiable stimuli such as emotional stress). Its pathogenesis is a multi-level vascular abnormality involving deficient endothelial vasodilating substances (notably nitric oxide), autonomic nervous system dysregulation causing norepinephrine-mediated vasospasm, and secondary activation of the clotting system (platelet aggregation and thromboxane release), which together produce episodic ischemia (pallor), cyanosis, and reactive hyperemia (erythema) in the digits. This mechanism situates Raynaud's within vascular medicine as a model of vasospastic disease linking endothelial, neural, and hemostatic pathophysiology.
Raynaud's phenomenon is classified theoretically into primary (idiopathic, cold-sensitive, often inherited), secondary (occurring in the setting of systemic autoimmune disease such as lupus or rheuma…