Fingernails were smashed, mild bruising and swelling can be relieved by cold compresses followed by hot compresses, serious need to seek medical treatment. 1. Mild bruising and swelling can be handled by cold compresses at first, which can avoid further bleeding and relieve pain, and after 10 to 24 hours, hot compresses can be used to promote the absorption of bruises and help reduce swelling. 2. If self-treatment fails to relieve, or the pain is obvious, you need to consult a doctor in time, you can carry out CT, X-ray and other auxiliary examination, to observe whether the phalangeal fracture occurs. Serious nail extraction treatment is needed to drain the blood, clean the wound and promote the growth of new nails. After nail extraction treatment, it is necessary to pay attention to the prevention of infection, avoid contact with raw water, and change the medication regularly.