A bruise that does not dissipate and becomes hard for 20 days is usually a bruise on the body surface and usually has no serious consequences. The patient can be observed for a few more days with the aid of hot compresses and massage. If the bruise can gradually dissipate or become soft, it indicates that it is gradually improving. If the bruising does not dissipate after hot compresses and massage, and there is no sign of softening, the bruising may be more severe, or may be caused by poor circulation, and may be a bruising sclerosis. Because long-term bruising can cause local tissue hypoxia, due to the inability to supply nutrients and metabolic products can not be discharged, coupled with the increase of reticular fibers in the tissue, resulting in the gradual mechanization of the hematoma, which in turn leads to local tissue atrophy and hardening, manifested as a hard mass. The bruise does not dissipate and becomes a hard mass, which can subside within 2 weeks in many patients, but in very few cases it may not subside after 20 days. If it does affect the aesthetics or in the joint area and affects joint movement, it can be treated surgically if necessary.