Unilateral coldness of the extremities suggests?

• A. An arterial occlusion
• B. Shock
• C. An environmental problem
• D. A venous occlusion

Answer: (A)

Unilateral coldness of a limb points to compromised arterial inflow to that limb, i.e., acute limb ischemia from an arterial occlusion. When an artery is blocked, distal tissues lose arterial blood supply, so the affected area becomes cool and pale, and pulses may be absent or weak. Pain, numbness, and changes in motor function often accompany this, reflecting evolving tissue ischemia. This pattern is localized to one limb, unlike shock where cold extremities result from overall poor perfusion and are typically bilateral. Venous occlusion tends to cause swelling and a different color/temperature profile, not a sudden, cool, pale limb. Environmental exposure could cause coldness but would usually relate to exposure history and often affect more than one limb if the environment is shared; the abrupt, unilateral presentation with ischemic signs makes arterial occlusion the most likely explanation.