One hand is swollen and one hand is normal, which may be due to unilateral hand swelling caused by frozen shoulder, cervical spondylosis and muscle strain. 1. Frozen shoulder: Due to the inflammation of unilateral shoulder joint, it may affect the blood circulation of shoulder and peripheral circulation of upper limb, and the venous return is blocked, and the patient may have arm swelling. 2. Cervical spondylosis: due to a series of degeneration of the cervical spine, such as cervical disc herniation and cervical osteophytes, the nerve roots innervating the hand are compressed, which may lead to abnormal discharges of the nerve roots, and then unilateral swelling of the hand occurs. 3. Muscle strain: when one side of the arm is subjected to abnormal pulling during labor or exercise, it leads to muscle damage. This causes a slowing of venous return in the distal limb, leading to unilateral hand swelling. When unilateral hand swelling occurs, it is recommended to consult a doctor in time, follow the doctor’s instructions for further examination, with the help of the doctor to clarify the cause, and targeted treatment or therapy.