While the chance of healing from the spinal cord being severed is very low, total paralysis below the site of damage may not be permanent in all cases. Oten, injury results in a concussion or contusion that leads to a temporary paralysis due to the swelling at that part of the spine.
Over time, as the swelling decreases, proper nerve functioning is restored. This phenomenon is referred to as spinal shock, and the related swelling generally decreases over a few days after a quick buildup just after the damage occurs.
Nerves that have been completely severed or degenerated, however, do not heal in time or with treatment. The damage to the nervous system functioning is usually lifelong and irreversible. If there is an increase of feeling and muscle control within the first week after an injury, there is a much greater chance of healing.