Itching inside the calf muscle may be caused by the performance of local repair after injury, or it may be caused by lumbar spine disease, diabetes and other conditions. 1. Repair after injury: the muscles of the calf mostly refer to the gastrocnemius muscle at the back of the calf, the flounder muscle and other large muscle groups, if the muscle groups of the calf have suffered trauma or infection and other conditions, in the process of the body to repair the muscle tissue, it may cause oxygen free radicals, prostaglandins and other mediators to accumulate, stimulate the surrounding nerve roots, the symptom of itchy inside the calf muscle. 2. Lumbar spine disease: lumbar spine disease may produce pressure on the nerve tissues innervating the calf muscles, causing abnormal sensation of the calf muscles, and the symptoms of itching inside the calf muscles may also appear, such as lumbar intervertebral disc herniation, spinal stenosis and lumbar spine slippage. 3. Diabetes mellitus: When diabetes mellitus occurs due to abnormal glucose metabolism of the body, it may cause ischemia, hypoxia and other pathological changes in the nerve tissues of the calf area, resulting in degeneration of the peripheral nerves, and the symptom of itching inside the calf muscles may also occur. The symptoms of itching inside the calf muscle alone sometimes can not accurately determine the cause, but also need to be combined with the characteristics of the medical history, other test results to make an accurate judgment, it is recommended to clarify the cause of the disease under the guidance of a doctor.