Stiff hands at night may be caused by improper sleeping posture, or may be caused by tendinitis, gout and other diseases. 1. Improper sleeping posture: If you sleep in the same position for a long time at night, such as sleeping on the arm, resulting in localized obstruction of blood circulation in the fingers, stiff hands can occur. If there is no other discomfort, it is a normal phenomenon, no need to worry too much, adjust the sleeping position. 2. Tenosynovitis: Tenosynovitis may be caused by chronic strain, long-term overexertion of the wrist joint, trauma, infection and other factors. Localized pain can occur, the affected joints have limited movement, and some patients may experience stiffness in their hands when they sleep at night. 3. Gout: the etiology and pathogenesis of gout have not been clearly defined, it may be caused by uric acid excretion disorder, drugs, excessive intake of purine-rich foods, alcohol consumption and other factors. Patients can appear local joint redness, swelling, dysfunction, pain and other symptoms, can be manifested in the night sleep stiff hands. There are many reasons that lead to the stiffness of the hands at night, and it is recommended that patients go to the regular hospital to find out the cause of the disease.