Raynaud's Disease

Episodic colour changes in fingers and toes — white, then blue, then red — triggered by cold or stress, caused by temporary spasm of the small arteries. Primary Raynaud's is common, mild, and runs in families; secondary Raynaud's, arriving later in life with other symptoms, can signal an underlying autoimmune condition.

Evidence synthesis: Primary Raynaud's involves hyperresponsive digital arteries — the vessels overreact to cold and stress with spasm; the mechanism is vascular over-sensitivity, not structural disease. Secondary Raynaud's is associated with connective tissue diseases (systemic sclerosis, lupus), and new onset after age 40, asymmetry, or abnormal nailfold capillaries are the clinical flags prompting autoimmune serology. Cold avoidance, hand-warming strategies, and smoking cessation are first-line with strong mechanistic and clinical support; smoking is a potent vasoconstrictor that measurably worsens attacks. A small randomised trial of fish oil in primary Raynaud's showed improved cold tolerance and delayed vasospasm onset; ginkgo has mixed trial data. Calcium channel blockers (nifedipine) are the evidence-based medication when attacks are frequent. Digital ulcers or fingertip sores signal secondary disease severity requiring specialist care.