Buerger's disease most commonly affects the small and medium sized arteries, veins, and nerves. Although the cause is unknown, there is a strong association with tobacco use or exposure. The arteries of the arms and legs become narrowed or blocked, causing lack of blood supply (ischemia) to the fingers, hands, toes, and feet. Pain occurs in the arms, hands and, more frequently, the legs and feet, even when at rest. With severe blockages, the tissue may die (gangrene), requiring amputation of the fingers and toes. Superficial vein inflammation and symptoms of Raynaud's occur commonly in patients with Buerger's disease. Histologic analysis of arterial specimens shows preservation of the internal elastic lamina. Best outcomes are associated with smoking cessation. No specific laboratory tests confirm or exclude the diagnosis of Buerger disease. The primary goal of a laboratory workup in patients thought to have the disease is to exclude other disease processes in the differential diagnosis. Tests often used as markers for the diagnosis of systemic vasculitis, such as the acute-phase reactants, are negative in Buerger disease.