Spinal cord injuries result from any force or condition that damages the bundle of nerves running through your vertebral column. About 18,400 new traumatic spinal cord injuries occur in the United States each year. The causes split into two broad categories: traumatic injuries from sudden physical force and non-traumatic injuries from medical conditions that gradually compress or damage the cord.
Traumatic Causes
Vehicle crashes are the single leading cause of traumatic spinal cord injury, closely followed by falls. Acts of violence, primarily gunshot wounds, and sports or recreation activities round out the most common causes. The relative importance of each cause shifts dramatically with age. Among adults 65 and older, falls account for roughly two-thirds of all spinal cord injuries, a share that has climbed steeply over the past two decades (from 28 percent in 1997–2000 to 66 percent in 2010–2012). In younger adults, car and motorcycle crashes dominate.
The average age at injury has risen from 29 years in the 1970s to 44 years since 2015, reflecting the aging population and the growing role of falls. Men are injured at about four times the rate of women, largely because of higher exposure to vehicle crashes, contact sports, and violence.
How Sports Injuries Happen
Sports-related spinal cord injuries most often involve the cervical spine, the section in your neck. Diving into shallow water is a classic scenario: the top of the head strikes the bottom, and the vertical force travels straight down the spine, compressing or fracturing the vertebrae and crushing the cord inside. Football produces a similar mechanism. CDC research on high school players found that more than half of football-related spinal cord injuries involved using the top of the helmet as the initial point of contact during a tackle or block. The force loads the spine axially, meaning straight down its length, while the neck is partially flexed. That combination is the mechanism most likely to cause permanent quadriplegia.
Players at greatest risk are those who tackle by flexing their necks and leading with the crown of the helmet. Rule changes banning “spearing” were introduced specifically to reduce this type of injury, though it still occurs.
Non-Traumatic Causes
Not all spinal cord injuries come from a sudden impact. Medical conditions can compress, inflame, or starve the cord of blood supply over days, weeks, or months. In one emergency department study published in Frontiers in Neurology, the three most common non-traumatic causes were cancer that had spread to the spine (33 percent of cases), inflammatory disorders (22 percent), and degenerative conditions like severe spinal stenosis or disc disease (19 percent). Infections affecting the spinal canal made up another share.
Cancer-related injuries happen when tumors from elsewhere in the body, most commonly lymphomas, lung cancer, or gastrointestinal cancers, metastasize to the vertebrae or the membranes surrounding the cord. As the tumor grows, it presses on nerve tissue. Degenerative causes work more slowly: years of arthritis or disc degeneration narrow the spinal canal until even a minor bump or fall can injure a cord that has almost no room left. Inflammatory conditions, including multiple sclerosis and certain autoimmune disorders, attack the cord’s protective insulation directly.
What Happens Inside the Spinal Cord
A spinal cord injury unfolds in two distinct phases, and understanding both helps explain why the damage often worsens before it stabilizes.
The first phase is the primary injury: the moment of impact. When compressive force exceeds what the tissue can tolerate, it tears nerve fibers, ruptures blood vessels, and damages the cells that insulate nerves. The cord is almost never completely severed. Instead, it’s bruised and partially torn. The maximum loss of function typically appears immediately because nerve signaling is disrupted by the direct cellular damage, bleeding, and massive shifts in the electrical environment around the cells. This initial damage is largely irreversible.
The second phase, called secondary injury, begins within minutes and can continue for days. Swelling and bleeding inside the cord spread above and below the original impact site, sometimes spanning several vertebral levels. Damaged blood vessels become leaky, causing fluid to build up inside cells and triggering an intense inflammatory response. This cascade of swelling, inflammation, and oxygen deprivation destroys tissue that survived the initial impact, effectively enlarging the injury. The gray matter at the cord’s center, which is rich in blood vessels, is especially vulnerable to this spreading hemorrhage. Much of emergency spinal cord injury treatment focuses on limiting this secondary damage, because it represents a window where intervention can still preserve function.
Who Is Most at Risk
Risk patterns have shifted over the decades. Young men between 16 and 30 once made up the overwhelming majority of new cases, driven by car crashes, sports, and violence. That group still faces high risk, but the population of people injured later in life is growing. Older adults are more vulnerable to cord injury from falls because age-related changes, including osteoporosis, narrowed spinal canals, and stiffer ligaments, mean less force is needed to cause serious damage. A fall from standing height that a 25-year-old walks away from can fracture vertebrae and injure the cord in someone over 70.
Occupations involving heights, high-speed vehicles, or contact with heavy machinery carry elevated risk. So do activities like horseback riding, skiing, and gymnastics, where high-energy falls or sudden deceleration can load the spine beyond its limits.