Twitching and pain at the back of the thigh may be caused by the following reasons: first, cold, when cold can lead to spasm of the thigh muscles, and the back of the thigh muscle twitching, then we need to get out of the cold environment early, pay attention to warmth, and early physical therapy; second, lack of calcium, lack of calcium can lead to tonic spasms of the leg muscles, that is, the symptom of twitching, which can be accompanied by numbness and nerve disorder symptoms. Second, calcium deficiency, calcium deficiency can also lead to tonic spasms of the leg muscles, that is, twitching symptoms, accompanied by numbness and nerve disorders, then we should check the blood test, if calcium deficiency, early calcium supplementation treatment; third, neurological diseases, when the peripheral nerves are stimulated, such as inflammation stimulation or the central nervous system is compressed, it can lead to twitching of the thighs, this time we need to check the neurological electromyography and magnetic resonance imaging to diagnose and treat.