In order to answer the question well, it would be important to know a bit more about any nail infections or trauma. However, we will assume that you damaged the nail, by slamming it in a car door or something similar, as this is the most common cause of this problem. Basically what happens when you damage a nail like this is that you often sever it from the part of the nail where new nail tissue is formed (underneath the cuticle) and you separate it from the nail bed. Over time, assuming the zone of nail growth under the cuticle has not been damaged, a new nail will grow in over the nail bed. Usually the old nail just fall off as this happens and, over a period of weeks to months, things return to normal. Occasionally, however, the old nail does not detach properly. If this is happening to you and it is uncomfortable, it may be necessary to remove the old nail manually. It is better to be seen by your primary care doctor
to see if this is the case. If so, they can likely remove it for you right there in the office.