Cramps are not necessarily a sign of cancer, but can also be caused by physiologic reasons, calcium deficiency, muscle diseases, etc. 1. Physiological reasons: When the patient’s lower limbs are over-fatigued, a large amount of lactic acid will accumulate and the symptoms of cramps will appear, which will return to normal after local physical therapy or rest. 2. Disease factors (1) Cancer: if the patient suffers from tumor, when the tumor keeps increasing and malignant transformation occurs, it may compress the nerve and affect the nerve function, and the symptom of muscle cramps will appear. (2) Calcium deficiency: when there are various reasons leading to the loss of calcium ions in the body or the intake of calcium is too little, it may cause hypocalcemia, and then muscle cramps may appear. (3) Muscle diseases: For example, muscle diseases such as myotonic dystrophy and polymyositis can cause cramps. Combine with creatine kinase, electromyography and other tests to confirm the diagnosis. If there are frequent cramps symptoms should be taken seriously, do not rule out and disease factors, should go to the hospital.