Foot numbness is commonly caused by these diseases, as follows: 1, the most common is the disease of the lumbar spine, such as lumbar disc herniation compression to the sciatic nerve; 2, if the elderly, pay attention to whether there is cerebrovascular disease, especially cerebral infarction; 3, part of the peripheral nerve disease, such as peripheral neuropathy of diabetes; 4, common squatting for a long time, sitting for a long time, these due to the compression of the lower extremities, will also cause nerve compression, will also lead to numbness of the lower extremities.