Hand cyst is a benign tumor caused by abnormal proliferation of tissues in the hand, and is considered to be related to tendon sheath cysts and sebaceous cysts. 1. Tendon sheath cysts: hand cysts have more causes, cysts are more common in the joints, mostly tendon sheath cysts. They are usually caused by damage to the joints of the fingers, resulting in herniation of the tendons and the phalangeal joints and the formation of hand cysts. If the hand cysts affect the activities, or when there is pain, it is recommended that surgery is needed for treatment. 2. Sebaceous cysts: Sebaceous cysts may also form on the localized skin of the hand. This condition is usually caused by a blockage of the skin follicles. If the sebaceous glands are blocked, the sebaceous glands that produce sebum will gather and form cysts. Most of these cysts are located on the surface of the skin of the hand, and if the cysts are large, surgical removal is usually required. Cysts on the hand, it is recommended to go to the hospital in time to improve the ultrasound diagnosis, as soon as possible to carry out regular treatment.