Elderly people are the most rapidly growing demographic in developed nations. Although they sustain traumatic injury less commonly than children and young adults, the mortality rate for trauma in the elderly is higher than in younger people. In the United States, this population accounts for 14% of all traumatic injuries, of which a majority are secondary to falls.

Common causes of head injury are motor vehicle traffic collisions, home and occupational accidents, falls, and assaults. Wilson's disease has also been indicative of head injury. According to the United States CDC, 32% of traumatic brain injuries (another, more specific, term for head injuries) are caused by falls, 10% by assaults, 16.5% by being struck or against something, 17% by motor vehicle accidents, 21% by other/unknown ways. In addition, the highest rate of injury is among children ages 0–14 and adults age 65 and older.

A progressive decline in central nervous system function leads to a loss of proprioception, balance and overall motor coordination, as well as a reduction in eye–hand coordination, reaction time and an unsteady gait. These degenerative changes are often accompanied by osteoarthritis (degenerative joint disease), which leads to a reduction in the range of motion of the head, neck and extremities. Furthermore, elderly people frequently take multiple medications for control of various diseases and conditions. The side effects of some of these medications may either predispose to injury, or may cause a minor trauma to result in a much more severe condition. For example, a person taking warfarin (Coumadin) and/or clopidogrel (Plavix) may experience a life-threatening intracranial hemorrhage after sustaining a relatively minor closed head injury, as a result of the defect in the hemostatic mechanism caused by such medications. The combined effects of these changes greatly predisposes elderly people to traumatic injury. Both the incidence of falls and the severity of associated complications increase with advancing age.

In children with uncomplicated minor head injuries the risk of intra cranial bleeding over the next year is rare at 2 cases per 1 million. In some cases transient neurological disturbances may occur, lasting minutes to hours. Malignant post traumatic cerebral swelling can develop unexpectedly in stable patients after an injury, as can post traumatic seizures. Recovery in children with neurologic deficits will vary. Children with neurologic deficits who improve daily are more likely to recover, while those who are vegetative for months are less likely to improve. Most patients without deficits have full recovery. However, persons who sustain head trauma resulting in unconsciousness for an hour or more have twice the risk of developing Alzheimer's disease later in life.

Head injury may be associated with a neck injury. Bruises on the back or neck, neck pain, or pain radiating to the arms are signs of cervical spine injury and merit spinal immobilization via application of a cervical collar and possibly a long board.If the neurological exam is normal this is reassuring. Reassessment is needed if there is a worsening headache, seizure, one sided weakness, or has persistent vomiting.

To combat overuse of Head CT Scans yielding negative intracranial hemorrhage, which unnecessarily expose patients to radiation and increase time in the hospital and cost of the visit, multiple clinical decision support rules have been developed to help clinicians weigh the option to scan a patient with a head injury. Among these are the Canadian Head CT rule, the PECARN Head Injury/Trauma Algorithm, and the New Orleans/Charity Head Injury/Trauma Rule all help clinicians make these decisions using easily obtained information and noninvasive practices.

Injury is damage to the body caused by external force. This may be caused by accidents, falls, hits, weapons, and other causes. Major trauma is injury that has the potential to cause prolonged disability or death.

In 2013, 4.8 million people died from injuries, up from 4.3 million in 1990. More than 30% of these deaths were transport-related injuries. In 2013, 367,000 children under the age of five died from injuries, down from 766,000 in 1990. Injuries are the cause of 9% of all deaths, and are the sixth-leading cause of death in the world.

While any number of injuries may occur during the birthing process. A number of specific conditions are well described. Brachial plexus palsy occurs in 0.4 to 5.1 infants per 1000 live birth. Head trauma and brain damage during delivery can lead to a number of conditions include: caput succedaneum, cephalohematoma, subgaleal hemorrhage, subdural hemorrhage, subarachnoid hemorrhage, epidural hemorrhage, and intraventricular hemorrhage.

The most common fracture during delivery is that of the clavicle (0.5%).

As many as 50–70% of people who survive traffic accidents have facial trauma. In most developed countries, violence from other people has replaced vehicle collisions as the main cause of maxillofacial trauma; however in many developing countries traffic accidents remain the major cause. Increased use of seat belts and airbags has been credited with a reduction in the incidence of maxillofacial trauma, but fractures of the mandible (the jawbone) are not decreased by these protective measures. The risk of maxillofacial trauma is decreased by a factor of two with use of motorcycle helmets. A decline in facial bone fractures due to vehicle accidents is thought to be due to seat belt and drunk driving laws, strictly enforced speed limits and use of airbags. In vehicle accidents, drivers and front seat passengers are at highest risk for facial trauma.

Facial fractures are distributed in a fairly normal curve by age, with a peak incidence occurring between ages 20 and 40, and children under 12 suffering only 5–10% of all facial fractures. Most facial trauma in children involves lacerations and soft tissue injuries. There are several reasons for the lower incidence of facial fractures in children: the face is smaller in relation to the rest of the head, children are less often in some situations associated with facial fractures such as occupational and motor vehicle hazards, there is a lower proportion of cortical bone to cancellous bone in children's faces, poorly developed sinuses make the bones stronger, and fat pads provide protection for the facial bones.

Head and brain injuries are commonly associated with facial trauma, particularly that of the upper face; brain injury occurs in 15–48% of people with maxillofacial trauma. Coexisting injuries can affect treatment of facial trauma; for example they may be emergent and need to be treated before facial injuries. People with trauma above the level of the collar bones are considered to be at high risk for cervical spine injuries (spinal injuries in the neck) and special precautions must be taken to avoid movement of the spine, which could worsen a spinal injury.

Sequelae can occur in both the mother and the infant after a traumatic birth.

Birth trauma is uncommon in the Western world in relation to rates in the third world. In the West injury occurs in 1.1% of C-sections.

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.

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.

The Orchard Sports Injury Classification System (OSICS) is used to classify injuries to enable research into specific sports injuries.

Injury mechanisms such as falls, assaults, sports injuries, and vehicle crashes are common causes of facial trauma in children as well as adults. Blunt assaults, blows from fists or objects, are a common cause of facial injury. Facial trauma can also result from wartime injuries such as gunshots and blasts.

Animal attacks and work-related injuries such as industrial accidents are other causes. Vehicular trauma is one of the leading causes of facial injuries. Trauma commonly occurs when the face strikes a part of the vehicle's interior, such as the steering wheel. In addition, airbags can cause corneal abrasions and lacerations (cuts) to the face when they deploy.

The chances that a person will suffer PTS are influenced by factors involving the injury and the person. The largest risks for PTS are having an altered level of consciousness for a protracted time after the injury, severe injuries with focal lesions, and fractures. The single largest risk for PTS is penetrating head trauma, which carries a 35 to 50% risk of seizures within 15 years. If a fragment of metal remains within the skull after injury, the risk of both early and late PTS may be increased. Head trauma survivors who abused alcohol before the injury are also at higher risk for developing seizures.

Occurrence of seizures varies widely even among people with similar injuries. It is not known whether genetics play a role in PTS risk. Studies have had conflicting results with regard to the question of whether people with PTS are more likely to have family members with seizures, which would suggest a genetic role in PTS. Most studies have found that epilepsy in family members does not significantly increase the risk of PTS. People with the ApoE-ε4 allele may also be at higher risk for late PTS.

Risks for late PTS include hydrocephalus, reduced blood flow to the temporal lobes of the brain, brain contusions, subdural hematomas, a torn dura mater, and focal neurological deficits. PTA that lasts for longer than 24 hours after the injury is a risk factor for both early and late PTS. Up to 86% of people who have one late post-traumatic seizure have another within two years.

It is not known whether PTS increase the likelihood of developing PTE. Early PTS, while not necessarily epileptic in nature, are associated with a higher risk of PTE. However, PTS do not indicate that development of epilepsy is certain to occur, and it is difficult to isolate PTS from severity of injury as a factor in PTE development. About 3% of patients with no early seizures develop late PTE; this number is 25% in those who do have early PTS, and the distinction is greater if other risk factors for developing PTE are excluded. Seizures that occur immediately after an insult are commonly believed not to confer an increased risk of recurring seizures, but evidence from at least one study has suggested that both immediate and early seizures may be risk factors for late seizures. Early seizures may be less of a predictor for PTE in children; while as many as a third of adults with early seizures develop PTE, the portion of children with early PTS who have late seizures is less than one fifth in children and may be as low as one tenth. The incidence of late seizures is about half that in adults with comparable injuries.

Concussions and other types of repetitive play-related head blows in American football have been shown to be the cause of chronic traumatic encephalopathy (CTE), which has led to player suicides and other debilitating symptoms after retirement, including memory loss, depression, anxiety, headaches, and also sleep disturbances.

The list of ex-NFL players that have either been diagnosed "post-mortem" with CTE or have reported symptoms of CTE continues to grow.

Concussions are proven to cause loss of brain function. This can lead to physical and emotional symptoms such as attention disorders, depression, headaches, nausea, and amnesia. These symptoms can last for days or week and even after the symptoms have gone, the brain still won't be completely normal. Players with multiple concussions can have drastically worsened symptoms and exponentially increased recovery time.

Researchers at UCLA have, for the first time, used a brain-imaging tool to identify a certain protein found in five retired NFL players. The presence and accumulation of tau proteins found in the five living players, are associated with Alzheimer's disease. Previously, this type of exam could only be performed with an autopsy. Scientists at UCLA created a chemical marker that binds to the abnormal proteins and they are able to view this with Positron Emission Tomography (PET) scan. Researcher at UCLA, Gary Small explains, "Providing a non-invasive method for early detection is a critical first step in developing interventions to prevent symptom onset and progression in CTE".

The nature of the head trauma also influences the risk of PTE. People who suffer depressed skull fractures, penetrating head trauma, early PTS, and intracerebral and subdural haematomas due to the TBI are especially likely to suffer PTE, which occurs in more than 30% of people with any one of these findings. About 50% of patients with penetrating head trauma develop PTE, and missile injuries and loss of brain volume are associated with an especially high likelihood of developing the condition. Injuries that occur in military settings carry higher-than-usual risk for PTE, probably because they more commonly involve penetrating brain injury and brain damage over a more widespread area. Intracranial hematomas, in which blood accumulates inside the skull, are one of the most important risk factors for PTE. Subdural hematoma confers a higher risk of PTE than does epidural hematoma, possibly because it causes more damage to brain tissue. Repeated intracranial surgery confers a high risk for late PTE, possibly because people who need more surgery are more likely to have factors associated with worse brain trauma such as large hematomas or cerebral swelling. In addition, the chances of developing PTE differ by the location of the brain lesion: brain contusion that occurs on in one or the other of the frontal lobes has been found to carry a 20% PTE risk, while a contusion in one of the parietal lobes carries a 19% risk and one in a temporal lobe carries a 16% chance. When contusions occur in both hemispheres, the risk is 26% for the frontal lobes, 66% for the parietal, and 31% for the temporal.

Prevention of suspension trauma is preferable to dealing with its consequences. Specific recommendations for individuals doing technical ropework are to avoid exhausting themselves so much that they end up without the energy to keep moving, and making sure everyone in a group is trained in single rope rescue techniques, especially the "single rope pickoff", a rather difficult technical maneuver that must be practiced frequently for smooth performance.

A liver injury, also known as liver laceration, is some form of trauma sustained to the liver. This can occur through either a blunt force such as a car accident, or a penetrating foreign object such as a knife. Liver injuries constitute 5% of all traumas, making it the most common abdominal injury. Generally nonoperative management and observation is all that is required for a full recovery.

The more severe the brain trauma is, the more likely a person is to suffer late PTE. Evidence suggests that mild head injuries do not confer an increased risk of developing PTE, while more severe types do. In simple mild TBI, the risk for PTE is about 1.5 times that of the uninjured population. By some estimates, as many as half of sufferers of severe brain trauma experience PTE; other estimates place the risk at 5% for all TBI patients and 15–20% for severe TBI. One study found that the 30-year risk of developing PTE was 2.1% for mild TBI, 4.2% for moderate, and 16.7% for severe injuries, as shown in the chart at right.

If someone is stranded in a harness, but is not unconscious or injured, and has something to kick against or stand on (such as a rock ledge or caving leg-loops) it is helpful for them to use their leg muscles by pushing against it every so often, to keep the blood pumping back to the torso. If the person is stranded in mid-air or is exhausted, then keeping the legs moving can be both beneficial and rather dangerous. On the one hand, exercising the leg muscles will keep the blood returning to the torso, but on the other hand, as the movements become weaker the leg muscles will continue to demand blood yet they will become much less effective at returning it to the body, and the moment the victim ceases moving their legs, the blood will immediately start to pool. "Pedaling an imaginary bicycle" should only be used as a last-ditch effort to prolong consciousness, because as soon as the "pedaling" stops, fainting will shortly follow. If it is impossible to rescue someone immediately, then it is necessary to raise their legs to a sitting position, which can be done with a loop of rigging tape behind the knees or specialized equipment from a rescue kit.

When workers are suspended in their safety harnesses for long periods, they may suffer from blood pooling in the lower body. This can lead to suspension trauma. Once a worker is back on the ground after a fall has been arrested on a fall protection system, a worker should be placed in the “W” position. The “W” position is where a worker sits upright on the ground with their back/chest straight and their legs bent so that their knees are in line with the bottom of their chin. For added stability, make sure that the worker’s feet stay flat on the ground. In this position, a KED board can still be used if there are any potential spinal injuries and a worker needs stabilization before transport.

Once the worker is in this position, they will need to stay in that position for at least 30 minutes. Try to leave the worker in this position until their symptoms begin to subside. The time in the “W” position will allow the pooled blood from the legs to be slowly re-introduced back into the body. By slowing the rate at which the pooled blood reaches different organs, you are giving the body more of an opportunity to filter the pooled blood and maintain internal homeostasis. http://www.rigidlifelines.com/blog/entry/suspension-traumasymptoms-and-treatment

Given its anterior position in the abdominal cavity and its large size, it is prone to gun shot wounds and stab wounds. Its firm location under the diaphragm also makes it especially prone to shearing forces. Common causes of this type of injury are blunt force mechanisms such as motor vehicle accidents, falls, and sports injuries. Typically these blunt forces dissipate through and around the structure of the liver. A large majority of people who sustain this injury also have another accompanying injury.

Chronic kidney disease, for example, is sometimes a sequela of diabetes, "chronic constipation" or more accurately "obstipation" (that is, difficulty in passing stool) is a sequela to an intestinal obstruction, and neck pain is a common sequela of whiplash or other trauma to the cervical vertebrae. Post-traumatic stress disorder may be a psychological sequela of rape. Sequelae of traumatic brain injury include headache and dizziness, anxiety, apathy, depression, aggression, cognitive impairments, personality changes, mania, psychosis.

Some conditions may be diagnosed retrospectively from their sequelae. An example is pleurisy.

Other examples of sequelae include those following neurological injury; including aphasia, ataxia, hemi- and quadriplegia, and any number of other changes that may be caused by neurological trauma. Note that these pathologies can be related to both physical and chemical traumas, as both can cause lingering neuron damage.

The phrase "status post", abbreviated in writing as "s/p", is used to discuss sequelae with reference to their cause. Clinicians typically use the phrase to refer to acute traumatic conditions. For example: "the patient had neck pain "status post" a motor vehicle accident".

Rheumatic fever is a nonsuppurative sequela of a primary infection of group A "Streptococcus" bacteria. Glomerulonephritis can also be a sequela of "Streptococcus pyogenes".

Ocular trauma is the fourth most common injury sustained in military combat today. In a pool of 387 randomly selected soldiers injured by blast trauma in Operation Iraqi Freedom, 329 (89%) sustained ocular trauma. Emergency treatment of resulting injuries falls under the realm of emergency care and effective patient triage, often incorporating protocols for blunt and penetrating trauma. As a result, physicians have devised a concise algorithm for the treatment of patients with ocular injuries secondary to blast trauma.

The degree of tissue disruption caused by a projectile is related to the size of the temporary versus permanent cavity it creates as it passes through tissue. The extent of cavitation, in turn, is related to the following characteristics of the projectile:

- Kinetic energy: KE = 1/2"mv" (where "m" is mass and "v" is velocity). This helps to explain why wounds produced by missiles of higher mass and/or higher velocity produce greater tissue disruption than missiles of lower mass and velocity.

- Impulse: IMP = "mv". The impulse is working in a couple with kinetic energy, featuring the same characteristics

- Yaw

- Deformation

- Fragmentation

The immediate damaging effect of a gunshot wound is typically severe bleeding, and with it the potential for hypovolemic shock, a condition characterized by inadequate delivery of oxygen to vital organs. In the case of traumatic hypovolemic shock, this failure of adequate oxygen delivery is due to blood loss, as blood is the means of delivering oxygen to the body's constituent parts. Devastating effects can result when a bullet strikes a vital organ such as the heart or lungs, or damages a component of the central nervous system such as the spine or brain.

Common causes of death following gunshot injury include exsanguination, hypoxia caused by pneumothorax, catastrophic injury to the heart and larger blood vessels, and damage to the brain or central nervous system. Additionally, gunshot wounds typically involve a large degree of nearby tissue disruption and destruction due to the physical effects of the projectile. Non-fatal gunshot wounds frequently have severe and long-lasting effects, typically some form of major disfigurement and/or permanent disability.

Gunshot injuries can vary widely from case to case since the location of the injury can be in any part of the body, with wide variations in entry point. Also, the path and possible fragmentation of the bullet within the body is unpredictable. The study of the dynamics of bullets in gunshot injuries is called terminal ballistics.

As a rule, all gunshot wounds are considered medical emergencies that require immediate treatment. Hospitals are generally required to report all gunshot wounds to police.

Diaphragmatic injuries are present in 1–7% of people with significant blunt trauma and an average of 3% of abdominal injuries.

A high body mass index may be associated with a higher risk of diaphragmatic rupture in people involved in vehicle accidents. It is rare for the diaphragm alone to be injured, especially in blunt trauma; other injuries are associated in as many as 80–100% of cases. In fact, if the diaphragm is injured, it is an indication that more severe injuries to organs may have occurred. Thus, the mortality after a diagnosis of diaphragmatic rupture is 17%, with most deaths due to lung complications. Common associated injuries include head injury, injuries to the aorta, fractures of the pelvis and long bones, and lacerations of the liver and spleen. Associated injuries occur in over three quarters of cases.

Visual outcomes for patients with ocular trauma due to blast injuries vary, and prognoses depend upon the type of injury sustained. The majority of poor visual outcomes arise from perforating injuries: only 21% of patients with perforating injuries with pre-operative light perception had a final best-corrected visual acuity (BCVA) better than 20/200. Collectively, patients who experienced choroidal hemorrhage, perforated or penetrated globes, retinal detachment, traumatic optic neuropathy, and subretinal macular hemorrhage carried the highest incidence rates of BCVAs worse than 20/200. Reports from Operation Iraqi Freedom (OIF) indicate that 42% of soldiers with globe injuries of any kind had a BCVA greater than or equal to 20/40 six months after injury, and soldiers with intraocular foreign bodies (IOFBs) retained 20/40 or better vision in 52% of studied cases.

Globe perforation, oculoplastic intervention, and neuro-ophthalmic injuries contribute significantly to reported poor visual outcomes. 21% of tertiary centers treating patients exposed to blast trauma reported traumatic optic neuropathy (TON) in their patients, although avulsion of the optic nerve and TON were reported in only 3% of combat injuries. In the event that a victim of globe penetrating trauma cannot perceive any light within two weeks of surgical intervention, the ophthalmologist may choose to enucleate as a preventative measure against sympathetic ophthalmia. However, this procedure is extremely rare, and current reports indicate that only one soldier in OIF has undergone enucleation in a tertiary care facility to prevent sympathetic ophthalmia.