The causes of leg cramps are often considered in three ways: first, abnormalities in the muscles of the legs. Second, abnormalities in the nerves of the legs. Third, cramps caused by systemic diseases. Abnormalities in the leg muscles are mostly seen in acute muscle injuries, including contusions, strains, lacerations, and chronic strain injuries due to local inflammation caused by strain to produce muscle irritation symptoms, which can lead to muscle dysfunction, involuntary spasms, contractions will appear in the leg always cramp symptoms. Neurological factors are often seen in the lower extremity nerve stimulation or disease, such as lumbar disc herniation compressing the sciatic nerve in the lower extremity, and high lumbar disc herniation causing compression of the femoral nerve, and also including the pear-shaped muscle syndrome in the hip leading to compression of the sciatic nerve. Cramping symptoms. Systemic diseases including calcium deficiency, metabolic diseases such as abnormal thyroid function, abnormal kidney function, and abnormal heart function can lead to changes in the local muscle environment and muscle dysfunction, resulting in frequent cramping symptoms.