Numbness in the thumb of the foot is mostly caused by the following reasons: the first condition is that the shoes worn are small, and the local blood circulation is impaired due to the long-term squeezing and friction. In the second case, the numbness is caused by local nerve compression due to prolonged standing and prolonged sitting in daily life. The third condition, due to lumbar disc herniation, lumbar spinal stenosis and other diseases, local compression, resulting in problems with the nervous system, inducing numbness. In the fourth case, numbness in the thumb of the foot is induced by inflammation of the peripheral nerve, cardiovascular and cerebrovascular diseases, and liver and kidney diseases. In case of numbness, patients should go to the hospital in time to identify the specific cause and then give targeted treatment.