Numbness of the big toe is not necessarily a precursor of a serious illness and has more causes. Common causes of numbness of the big toe include prolonged compression of nerves, peripheral neuropathy (diabetic lesions), lumbar herniation, lumbar spinal stenosis, compression of nerves, vascular disease of the lower limbs, and cerebral infarction. 1. Prolonged compression of nerves: this kind of general numbness in the hands and feet in a short period of time to eliminate, there will not be a big problem. 2. Peripheral neuropathy (diabetic lesions): diabetes-induced peripheral neuropathy, often symmetrical pain and sensory abnormalities, lower extremity symptoms are more common than upper extremity. Sensory abnormalities include numbness, ant walking, insect crawling, heat, electric shock-like sensation, often from the distal toes up to the knee, patients have to wear socks and gloves-like sensory abnormalities. 3. Lumbar herniation or lumbar spinal stenosis compression of nerves: after lumbar disc herniation or lumbar spinal stenosis, it will affect the surrounding blood vessels and nerves, and if it affects the nerves, it will cause numbness of the lower limbs on the outer side of the thighs, soreness and numbness in the lower leg or numbness in the toes. 4. Lower limb vascular disease: lesions are mostly seen in the small arteries below the knee joint, such as anterior tibial, posterior tibial and dorsalis pedis arteries, which cause coldness and numbness of the limbs and other symptoms. 5. If the numbness of the big toe is accompanied by numbness of the hand on the same side, while the other side is completely normal, it may be the precursor of cerebral infarction, and requires urgent medical treatment. There are many reasons for numbness of the feet, and it is important to note that long-term chronic numbness of the feet in the elderly, which cannot be relieved, should also be considered as a possible cause of malignant tumors. The numbness of the big toe alone can not accurately determine the cause, but also need to be combined with the characteristics of the medical history, other test results in order to make an accurate judgment, it is recommended to clarify the cause of the disease under the guidance of a doctor.