Numbness in the sole of the foot is commonly caused by the following reasons: First, it is considered to be caused by a lumbar disc herniation, when the disc herniation compresses the sacral 1 nerve root, numbness in the outer ankle, lateral foot and sole of the foot can occur. Second, consider ankle canal syndrome, ankle canal syndrome refers to the compression of the cervical nerve at the ankle canal, which often causes abnormal skin sensation in the area innervated by the medial plantar nerve and the lateral plantar nerve, which will manifest as plantar numbness and discomfort. Thirdly, consider that it is caused by chronic diseases such as diabetes, especially in the late stage of diabetes, peripheral neuropathy may appear, which often can be manifested as numbness in the extremities, including numbness in the hands and numbness in the feet.