After a nail separates from the nail bed for whatever reason, it will not reattach. A new nail will have to grow back in its place. Nails grow back slowly, taking about 6 months for a fingernail and up to 18 months for a toenail.
Why Can’t a Cracked Nail Grow Back Together?
Nails, like hair, are composed of protein and fat and are not living tissue. They are produced by the nail matrix cells located at the base of the nail, in the whitish, moon-shaped area called the lunula. If the nail matrix is not damaged, the nail is typically capable of regrowth.
However, once a nail has detached from the nail bed, it cannot reattach or be repaired. The nail will need to grow back entirely from the nail matrix. This process takes time, as nails grow slowly – around 0.13 inches per month for fingernails and about half that rate for toenails.
What Should You Do If Your Nail Is Cracked or Detached?
If the entire nail is detached, there is nothing that can be done to reattach it. The best course of action is to remove any unattached remnants of the nail and clean the nail bed to prevent infection. The exposed nail bed can then be covered with petroleum jelly or antibiotic ointment and a bandage.
If only a portion of the nail is detached, the non-adhering part can be removed, and the remaining attached portion can be left in place. Again, the area should be cleaned and dressed to prevent infection.
In either case, the nail will need to regrow from the matrix, which can take several months. Seeking medical attention is recommended if there are signs of infection, significant damage to the surrounding tissues, or if the injury is particularly severe.