Causes of thigh numbness include physiologic factors, lumbar disc herniation, intracranial diseases, lateral femoral dermatitis, etc. 1. Physiological numbness: physiological numbness of the lower limbs caused by pressure on the thighs or buttocks due to prolonged and incorrect sitting posture, and return to normal after lifting the compression. 2. Lumbar intervertebral disc herniation: mainly caused by the compression of the nerve root of lumbar vertebrae, manifested as persistent dull pain in the lumbar region, pain radiating to the lower limbs on the affected side, and sensory impairment of the lower limbs. 3. Intracranial diseases: including cerebral infarction, cerebral hemorrhage, intracranial tumors and so on. After the onset of intracranial sensory center is damaged, it can be manifested as sensory dysfunction of the lower limbs, such as numbness of the thighs and other symptoms, which can be clearly diagnosed by CT or MRI. 4. Lateral femoral cutaneous neuritis: onset of numbness in the upper 2/3 of the thigh. Symptoms can be improved by acupuncture treatment and nutritional nerve treatment. There are other causes of thigh numbness, such as trauma, etc., if the persistence of non-relief, it is recommended to seek timely medical care, improve the relevant examinations, to clarify the cause of the disease, and then follow the doctor’s instructions for targeted treatment, so as to avoid delaying the condition.