Inability to feel heat and cold and pain in the left leg is related to high femoral nerve injury, spinal cord cavernous disease, cerebral hemorrhage, etc. Conservative treatment and surgical treatment can be given according to the condition. 1. High femoral nerve injury: it can be categorized into 4 types depending on the type of sensation, i.e. pain loss, temperature loss, touch loss and deep sensation loss, etc. Depending on the severity of the disease, conservative treatment and surgery can be given. According to the severity of the disease, conservative treatment and surgical treatment can be given. For mild blunt femoral nerve contusion, peripheral neurotrophic drugs (vitamin B1 and methylcobalamin) can be given, and microwave physiotherapy can be used to promote its functional recovery. For severe blunt femoral nerve contusion, if the intraneural hematoma is obvious and the crushing is severe, surgical treatment can be given, and the hematoma can be removed by peeling the nerve periphery, and then the nerve periphery can be loosened. Sharp force injury of femoral nerve, the nerve needs to be sutured in one stage, and physical therapy, acupuncture, local drug iontophoresis, functional exercise, etc. can be given after the operation. 2. Spinal Cord Cavernous Disease: it can lead to limb pain and temperature sensory loss, in mild cases, nutritional nerve treatment (methylcobalamin, vitamin B1) can be given, and in severe cases, surgical treatments such as occipital foramen magnum decompression surgery and internal drainage of spinal cord cavernous canals can be given. 3. Cerebral hemorrhage: it can cause hemiparesis and insensibility of one side of the limb. Oxygen intake, bed rest, control of blood pressure, reduction of cerebral edema (mannitol), nutrition of nerve cells (cytarabine, cerebral protein hydrolysate), rehabilitation therapy, surgical treatment and other treatments can be given. The lack of sensation of heat and cold and pain in the left leg may also be caused by other reasons, it is recommended to improve the examination and give standardized treatment after clarifying the cause, and not to self-medication, so as not to cause adverse consequences.