Injury in humans
An injury is any physiological damage to living tissue[1] caused by immediate physical stress. Injuries to humans 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.
Injury
Traumatic, burn, toxic, overuse
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.
Classification systems[edit]
The World Health Organization (WHO) developed the International Classification of External Causes of Injury (ICECI). Under this system, injuries are classified by mechanism of injury, objects/substances producing injury, place of occurrence, activity when injured, the role of human intent, and additional modules. These codes allow the identification of distributions of injuries in specific populations and case identification for more detailed research on causes and preventive efforts.[5]
The United States Bureau of Labor Statistics developed the Occupational Injury and Illness Classification System (OIICS). Under this system injuries are classified by nature, part of body affected, source and secondary source, and event or exposure. The OIICS was first published in 1992 and has been updated several times since.[6] The Orchard Sports Injury and Illness Classification System (OSIICS), previously OSICS, is used to classify injuries to enable research into specific sports injuries.[7][8]
The injury severity score (ISS) is a medical score to assess trauma severity.[9][10] It correlates with mortality, morbidity, and hospitalization time after trauma. It is used to define the term major trauma (polytrauma), recognized when the ISS is greater than 15.[10] The AIS Committee of the Association for the Advancement of Automotive Medicine designed and updates the scale.
Mechanisms[edit]
Trauma[edit]
Traumatic injury is caused by an external object making forceful contact with the body, resulting in a wound. Major trauma is a severe traumatic injury that has the potential to cause disability or death. Serious traumatic injury most often occurs as a result of traffic collisions.[11] Traumatic injury is the leading cause of death in people under the age of 45.[12]
Blunt trauma injuries are caused by the forceful impact of an external object. Injuries from blunt trauma may cause internal bleeding and bruising from ruptured capillaries beneath the skin, abrasion from scraping against the superficial epidermis, lacerated tears on the skin or internal organs, or bone fractures. Crush injuries are a severe form of blunt trauma damage that apply large force to a large area over a longer period of time.[11] Penetrating trauma injuries are caused by external objects entering the tissue of the body through the skin. Low-velocity penetration injuries are caused by sharp objects, such as stab wounds, while high-velocity penetration injuries are caused by ballistic projectiles, such as gunshot wounds or injuries caused by shell fragments.[13] Perforated injuries result in an entry wound and an exit wound, while puncture wounds result only in an entry wound. Puncture injuries result in a cavity in the tissue.[14]
Locations[edit]
Abdomen[edit]
Abdominal trauma includes injuries to the stomach, intestines, liver, pancreas, kidneys, gallbladder, and spleen. Abdominal injuries are typically caused by traffic accidents, assaults, falls, and work-related injuries, and physical examination is often unreliable in diagnosing blunt abdominal trauma. Splenic injury can cause low blood volume or blood in the peritoneal cavity. The treatment and prognosis of splenic injuries are dependent on cardiovascular stability.[28] The gallbladder is rarely injured in blunt trauma, occurring in about 2% of blunt abdominal trauma cases. Injuries to the gallbladder are typically associated with injuries to other abdominal organs.[29] The intestines are susceptible to injury following blunt abdominal trauma.[30] The kidneys are protected by other structures in the abdomen, and most injuries to the kidney are a result of blunt trauma.[31] Kidney injuries typically cause blood in the urine.[32]
Due to its location in the body, pancreatic injury is relatively uncommon but more difficult to diagnose. Most injuries to the pancreas are caused by penetrative trauma, such as gunshot wounds and stab wounds. Pancreatic injuries occur in under 5% of blunt abdominal trauma cases. The severity of pancreatic injury depends primarily on the amount of harm caused to the pancreatic duct.[33] The stomach is also well protected from injury due to its heavy layering, its extensive blood supply, and its position relative to the rib cage. As with pancreatic injuries, most traumatic stomach injuries are caused by penetrative trauma, and most civilian weapons do not cause long-term tissue damage to the stomach. Blunt trauma injuries to the stomach are typically caused by traffic accidents.[34] Ingestion of corrosive substances can cause chemical burns to the stomach.[19] Liver injury is the most common type of organ damage in cases of abdominal trauma.[35] The liver's size and location in the body makes injury relatively common compared to other abdominal organs, and blunt trauma injury to the liver is typically treated with nonoperative management.[36] Liver injuries are rarely serious, though most injuries to the liver are concomitant with other injuries, particularly to the spleen, ribs, pelvis, or spinal cord.[35] The liver is also susceptible to toxic injury, with overdose of paracetamol being a common cause of liver failure.[37]
Social and psychological aspects[edit]
Injuries often cause psychological harm in addition to physical harm. Traumatic injuries are associated with psychological trauma and distress, and some victims of traumatic injuries will display symptoms of post-traumatic stress disorder during and after the recovery of the injury. The specific symptoms and their triggers vary depending on the nature of the injury.[67] Body image and self-esteem can also be affected by injury. Injuries that cause permanent disabilities, such as spinal cord injuries, can have severe effects on self-esteem.[68][69] Disfiguring injuries can negatively affect body image, leading to a lower quality of life. Burn injuries in particular can cause dramatic changes in a person's appearance that may negatively affect body image.[70][71][72]
Severe injury can also cause social harm. Disfiguring injuries may also result in stigma due to scarring or other changes in appearance.[73][74] Certain injuries may necessitate a change in occupation or prevent employment entirely. Leisure activities are similarly limited, and athletic activities in particular may be impossible following severe injury. In some cases, the effects of injury may strain personal relationships, such as marriages.[75] Psychological and social variables have been found to affect the likelihood of injuries among athletes. Increased life stress can cause an increase in the likelihood of athletic injury, while social support can decrease the likelihood of injury.[76][77] Social support also assists in the recovery process after athletic injuries occur.[78]