Frozen shoulder patients have reduced shoulder activities at night, inflammatory factors tend to accumulate in the shoulder, and patients focus more on the shoulder at night, so the pain may be more severe at night, and if the symptoms persist, it is recommended to seek medical treatment in time. 1. Accumulation of inflammatory factors: Patients will carry out shoulder activities during the day, which can promote local blood circulation and take away the inflammatory factors. Reduced activities at night may cause accumulation of inflammatory factors in the shoulder, resulting in pain. 2. Concentration of patients’ attention: patients’ attention may be scattered during the daytime, while patients’ attention is more concentrated at night, coupled with the excitation of the vagus nerve at night and the lowering of the pain threshold, patients are more likely to have pain. Frozen shoulder patients may have more pain at night due to the above reasons. If patients often have shoulder pain at night, it is recommended to go to the hospital for timely examination and timely treatment by the doctor.