Following injury, the body heals by forming scar tissue, a natural repair mechanism that closes wounds and restores structural integrity. Nerves, specialized cells, form the body’s communication network, transmitting sensations like touch, pain, and temperature from the skin and other organs to the brain. Understanding the relationship between scar tissue and these sensory pathways is a common area of inquiry.
What Happens to Nerves During Injury and Healing
When an injury occurs, nerve endings in the affected area are often severed or damaged. This disruption means electrical signals that transmit sensation cannot reach their destination effectively. As the body initiates repair, it forms scar tissue, which differs from original tissue.
Scar tissue is primarily composed of collagen fibers, laid down in a less organized, haphazard pattern compared to healthy skin. This dense, fibrous matrix is largely aneural, meaning it lacks functional nerve endings. New nerves typically do not grow directly into this dense scar tissue, limiting sensation from within the scar itself.
Sensation in Scarred Areas
Even though scar tissue contains few functional nerves, individuals frequently experience various sensations in and around scarred areas. Original nerve damage can lead to complete numbness if nerve pathways are fully severed. Conversely, partial nerve damage or irritation can cause heightened sensitivity, pain, or tingling sensations.
These sensations typically stem from intact nerves around the scar’s periphery or from disorganized attempts at nerve regeneration at its edges. Damaged nerve endings can form painful bundles called neuromas. The tightness and inflexibility of scar tissue can also exert pressure on surrounding healthy nerves, leading to pain or altered sensation.
The Body’s Attempts at Nerve Repair
The peripheral nervous system, which includes nerves outside the brain and spinal cord, possesses a capacity for regeneration. Following an injury, peripheral nerves can attempt to regrow, with axons sometimes regenerating at approximately one inch per month. This regeneration involves nerve cells trying to reconnect and re-establish their pathways.
Despite this inherent ability, the dense, unorganized structure of scar tissue often presents a significant physical barrier to effective nerve regrowth. Scar tissue can impede regenerating nerve fibers from reaching their original targets, preventing full restoration of sensation or motor function. This obstruction is a primary reason why full sensation is often not restored in areas with large or deep scars.