The reason why frozen shoulder hurts so much at night may be that the sensation of pain is enhanced at night and the inflammatory factors that stimulate pain are increased. 1. Enhanced sensation of pain: during the daytime due to the noise, will be distracted from the pain, the night noise focus on the pain area, thus feeling the pain at night than during the day. 2. Increase of inflammatory factors stimulating pain: pain is caused by inflammatory factors produced by inflammation to stimulate the local tissues, nerves and sensations, and at night, due to static activities, blood circulation will slow down so that the inflammatory factors produced by frozen shoulder will be accumulated in larger quantities, which will aggravate the local pain. Frozen shoulder pain at night may have other reasons, such as cold, etc., should go to the regular hospital, the doctor according to the specific condition to determine the cause of the disease, for the cause of the correct treatment.