Whether the nail can grow back after it has been smashed and detached from the root depends on the specific condition. If the nail bed and root have not been damaged, it is usually possible to grow a new nail; if the nail bed and root have been severely damaged, it is more difficult to grow a new nail. It usually takes a few months for the nail to grow back after it has been smashed off. In addition, during the recovery period, the patient needs to protect the nail bed by wrapping the affected area with medical gauze after sterilization. It is important to prevent the fingers from coming into contact with caustic substances, such as detergents and other harsh washes. It is also necessary to pay attention to supplement some calcium and protein to promote the rapid growth of nails. It is also necessary to avoid physical contact with patients with gray nails, so as not to be infected with gray nails. It is recommended that patients go to regular hospitals for consultation and standardized treatment under the guidance of doctors. During the treatment and recovery period, the fingers should not be overly forceful to prevent secondary damage to the nails; and do a good job of daily care, so as to avoid infection and affect nail regeneration.