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. It takes about 6 months for a fingernail and up to 18 months for a toenail to grow back.

How long does it take to regrow a thumb nail?

If the visible part of your fingernails becomes detached due to an injury, the nail will grow back on its own. But it will require some patience on your part. For the average adult, fingernails grow about 1/10 of an inch a month. That means it can take up to six months for your fingernail to grow back to its full size.

How do you know if your nail will never grow back?

Nail growth will usually resume at a faster rate and steady after about 100 days. You may notice the nail appears thicker than usual. The extent of the injury often depends on where it occurs. If you have a deep cut or trauma to the germinal matrix at the base of the nail, it's possible the nail may never grow back.