An injury is any physiological damage to living tissue caused by immediate physical stress. An injury can occur intentionally or unintentionally and may be caused by blunt trauma, penetrating trauma, burning, toxic exposure, asphyxiation, or overexertion. Injuries can occur in any part of the body, and different symptoms are associated with different injuries. Treatment of a major injury is typically carried out by a health professional and varies greatly depending on the nature of the injury. Traffic collisions are the most common cause of accidental injury and injury-related death among humans. Injuries are distinct from chronic conditions, psychological trauma, infections, or medical procedures, though injury can be a contributing factor to any of these. Several major health organizations have established systems for the classification and description of human injuries. Occurrence
Injuries may be intentional or unintentional. Intentional injuries may be acts of violence against others or self-harm against ones own person. Accidental injuries may be unforeseeable or they may be caused by negligence The most common types of unintentional injuries in order are traffic accidents, falls, drowning, burns, and accidental poisoning. Certain types of injuries are more common in developed countries or developing countries. Traffic injuries are more likely to kill pedestrians than drivers in developing countries. Scalding burns are more common in developed countries, while open-flame injuries are more common in developing countries.As of 2021, approximately 4.4 million people are killed due to injuries each year worldwide, constituting nearly 8% of all deaths. 3.16 million of these injuries are unintentional and 1.25 million are intentional.
Stress fractures occur when the bone is overused or suffers under excessive or traumatic pressure, often during athletic activity. Hematomas occur immediately following a bone fracture, and the healing process often takes from six weeks to three months to complete, though continued use of the fractured bone will prevent healing. Articular cartilage damage may also affect function of the skeletal system, and it can cause posttraumatic osteoarthritis. Unlike most bodily structures, cartilage cannot be healed once it is damaged. Nervous system
Injuries to the nervous system include brain injury, spinal cord injury, and nerve injury. Trauma to the brain causes traumatic brain injury (TBI), causing "long-term physical, emotional, behavioral, and cognitive consequences". Mild TBI, including concussion, often occurs during athletic activity, military service, or as a result of untreated epilepsy, and its effects are typically short-term. More severe injuries to the brain cause moderate TBI, which may cause confusion or lethargy, or severe TBI, which may result in a coma or a secondary brain injury. TBI is a leading cause of mortality. Approximately half of all trauma-related deaths involve TBI. Non-traumatic injuries to the brain causeacquired brain injury (ABI). This can be caused by stroke, a brain tumor, poison, infection, cerebral hypoxia, drug use, or the secondary effect of a TBI.Injury to the spinal cord is not immediately terminal, but it is associated with concomitant injuries, lifelong medical complications, and reduction in life expectancy. It may result in complications in several major organ systems and a significant reduction in mobility or paralysis.