Lateral thigh skin sensory numbness can be caused by the following causes: 1, dermatome neuritis, dermatome neuritis can have sensory numbness in the lateral thigh dermatome innervation area, often the size of a palm area, this time to early physical examination to diagnose, early oral nerve nutrient drug therapy and physical therapy; 2, lumbar disc protrusion, lumbar disc protrusion for high disc protrusion, such as lumbar 1/2 and lumbar 2/3 of the The herniated disc can have sensory numbness of the skin on the outer thigh, which is due to the herniated disc compressing the nerves around the disc as well as the nerve roots, resulting in sensory numbness of the skin on the outer thigh. In this case, CT and MRI of the lumbar disc should be examined for diagnosis and early treatment.