There are many causes (see table Some Causes of Nontraumatic Limb Pain) but the most common are the following: Deep venous thrombosis (DVT) Cellulitis Radiculopathy Uncommon but serious causes that require immediate diagnosis and treatment include Acute arterial occlusion Deep soft-tissue infection Acute coronary ischemia (manifesting with only referred arm pain) Table Evaluation of Limb Pain It is important to exclude acute arterial occlusion.