Numbness" can be used by patients to describe various symptoms, including loss of sensation, abnormal sensations, and weakness or paralysis. However, numbness is actually loss of sensation, either partial (hypesthesia) or complete (anesthesia). Numbness may involve the 3 major sensory modalities—light touch, pain and temperature sensation, and position and vibration sensation—to the same or different degrees.
Numbness is often accompanied by abnormal sensations of tingling (pins-and-needles) unrelated to a sensory stimulus (paresthesias). Other manifestations (eg, pain, extremity weakness, nonsensory cranial nerve dysfunction) may also be present depending on the cause. Adverse effects of chronic numbness include difficulty walking and driving and increased risk of falls. In addition, infections, diabetic foot ulcers, and injuries may not be recognized, leading to delayed treatment.