There are several possible causes of ankle numbness: first, dermatome neuritis, if the dermatome nerve at the ankle has chronic inflammation, the ankle numbness in the dominant area can appear. Third, lumbar spine diseases, when the lumbar spine has lumbar spinal stenosis, lumbar disc herniation and lumbar spine slippage, ankle numbness can occur, then the diagnosis should be made by X-ray, CT and MRI of the lumbar spine; fourth, pear-shaped muscle syndrome, if the pear-shaped muscle syndrome is serious, compression of the sciatic nerve can also lead to ankle numbness, then the diagnosis should be made by X-ray, CT and MRI of the lumbar spine; fourth, pear-shaped muscle syndrome, if the pear-shaped muscle syndrome is serious, compression of the sciatic nerve can also lead to ankle numbness. Early physical examination and electromyography are required for diagnosis.