The right side of the trapezius muscle is high and the left side is low, and its common causes include trapezius strain, trapezius strain, cervical spondylosis, scoliosis and so on. 1. Trapezius strain: If long-term bad posture can cause right trapezius strain, the right muscle is easy to spasm and tension, resulting in trapezius muscle elevation, and the left side of the pair is more obvious, and there will be a sense of pain when pressed. 2. Trapezius muscle strain: after straining the right trapezius muscle, swelling and pain can occur, higher than the left side. 3. Cervical spondylosis: When cervical spondylosis attacks compress the nerve roots, it can lead to spasm and tension of the innervated trapezius muscle, resulting in an increase in the trapezius muscle. 4. Scoliosis: When scoliosis occurs, the right shoulder joint can be moved upward, resulting in the illusion that the right trapezius muscle is elevated, and there is no pain when the trapezius muscle is pressed. When the trapezius muscle is high on the right side and low on the left side, it is recommended to consult a doctor in time to clarify the cause of the disease, and then carry out the appropriate treatment.