Raynaud disease

Raynaud disease is a condition that affects the small blood vessels in the fingers and toes, causing them to narrow excessively in response to cold or stress. This narrowing reduces blood flow, leading to episodes where the affected areas turn white or blue and feel cold and numb. When blood flow returns, the skin may turn red and throb or tingle. The condition primarily involves the circulatory system and can cause discomfort and temporary changes in skin color. It is more common in women and often begins in young adulthood. While it usually affects the fingers and toes, it can also involve the ears, nose, or lips. The main health impact is related to these episodic blood flow changes and their symptoms.

Raynaud disease is a primary vasospastic disorder characterized by episodic, reversible digital ischemia due to exaggerated vasoconstriction of small arteries and arterioles in response to cold or emotional stress. It is caused by hyperactivation of the sympathetic nervous system leading to intense alpha-adrenergic receptor-mediated vasospasm without underlying structural vascular disease. The hallmark clinical presentation includes a triphasic color change of the digits: pallor (white) from ischemia, cyanosis (blue) from deoxygenation, and rubor (red) during reperfusion. It is distinguished from secondary Raynaud phenomenon by the absence of associated connective tissue disease or vascular pathology. The condition is significant because recurrent ischemia can cause pain, ulceration, or rarely digital gangrene. Diagnosis is clinical, supported by normal nailfold capillaroscopy and absence of autoantibodies. It primarily affects the peripheral microvasculature and is a functional rather than structural vascular disorder.