Muscle tightness and hardness may be caused by physiological factors and pathological factors such as high muscle tension and muscle spasm. 1. Physiological factors: some people will sweat a lot after a long period of exercise or electrolyte disorders, resulting in muscle tightness and hardness. Generally, the symptoms can be relieved by rest and relaxation, which is a normal phenomenon. 2. Pathological factors (1) Excessive muscle tension: For example, some diseases of the nervous system and cerebrovascular system can lead to abnormal nerve conduction, resulting in excessive muscle tension. For example, Parkinson’s disease, cerebral hemorrhage, cerebral thrombosis and other diseases will lead to high muscle tension, making the muscles tight and hard. (2) Muscle spasm: It is a kind of spontaneous tonic contraction of muscles, and muscle spasm will lead to tightness and hardness of muscles, and muscle spasm that occurs in calves and toes is the most common, which will lead to tightness and hardness of muscles. If the symptoms of muscle tightness and stiffness are not relieved after lifestyle modification, you should consult a doctor in time to clarify the cause of the disease and treat it under the guidance of the doctor.