The length of time it takes for a nail injury to heal depends on several different factors, including whether the nail broke off entirely or partially, if the nail bed is damaged, and how severe the injury is! For minor nail injuries that do not require medical attention, wherein the nail is still attached to the nail bed and leaves the nail bed undamaged, a few days should suffice for healing. However, if the nail falls off, is partially separated from the nail bed, or the nail bed is damaged, it will take significantly longer. It takes about seven to 10 days for a nail bed to heal itself after a nail has fallen off and around three to six months for the fingernail to grow back, or 12 to 18 months for a toenail. If you have experienced a nail avulsion, in which the nail and nail bed partially separate from the rest of the finger, it should heal within a few weeks. If the bone in your toe or finger is broken, it will take about four weeks to heal. For a subungual hematoma, in which blood is trapped between the nail and nail bed, it should completely heal within two to three months for a fingernail and within nine months for a toenail.