The time it takes a pinched nerve in the back to heal depends on what caused the pinched nerve. For example, a pinched nerve caused by poor posture may only take a few days to a week to heal. It can take between 4-6 weeks for a pinched nerve to heal when it is due to injury or a herniated disc. It might not heal on its own when due to a condition like arthritis. A pinched nerve can lead to chronic pain or permanent nerve damage in some cases.