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.

A gunshot wound (GSW) is a form of physical trauma sustained from the discharge of arms or munitions. The most common forms of ballistic trauma stem from firearms used in armed conflicts, civilian sporting, recreational pursuits and criminal activity. Ballistic trauma can be fatal or cause long-term consequences.

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.

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.

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 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.

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 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.

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.

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.

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.

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.

The United States Department of Defense classifies IEDs as explosive machines that are constructed exclusively (i.e., without mass production) and result in the direct physical harm of surrounding individuals. The use of these bombs by insurgents has been the number one cause of death and injury among Coalition soldiers since the start of Operation Iraqi Freedom in April 2003. Detonation of the IED occurs remotely or as victim-induced mechanical disturbance. Further classification of IEDs falls under the mechanism of delivery – vehicle-based, boat-borne, animal-borne, suicide bomber – and the resultant effect upon detonation:

- Explosive: Bombs of this nature incorporate chemicals and substances that result in the formation of a large blast; may incorporate pyrotechnics. Often employs shrapnel to inflict harm by mechanical trauma.

- Incendiary: utilize highly exothermic chemical processes to initiate the rapid spread of fire and pyrotechnic damage

- Chemical: Bombs in this class include noxious chemical materials that may cause a patho-physiological response in individuals exposed to the blast area during and post-explosion.

- Biological: Much like the chemical-type, with the exception that biological bombs use vector-borne pathogens or other biohazardous materials to initiate a patho-physiological response in exposed individuals.

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.

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%).

Virtually all organ systems experience a progressive decline in function as a result of the aging process. One example is a decline in circulatory system function caused in part by thickening of the cardiac muscle. This can lead to congestive heart failure or pulmonary edema.

Atrophy of the brain begins to accelerate at around seventy years of age, which leads to a significant reduction in brain mass. Since the skull does not decrease in size with the brain, there is significant space between the two when this occurs which puts the elderly at a higher risk of a subdural hematoma after sustaining a closed head injury. The reduction of brain size can lead to issues with eyesight, cognition and hearing.

Blunt splenic trauma most often occurs in automobile accident victims, in which it is a leading cause of internal bleeding. However, any type of major impact directed to the spleen may cause splenic trauma. This can happen in bicycling accidents, when the handlebar is forced into the left subcostal margin, and into the spleen. The degree of injury ranges from subcapsular hematoma, to splenic rupture.

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.

A significant complication of diaphragmatic rupture is traumatic diaphragmatic herniation: organs such as the stomach that herniate into the chest cavity and may be strangulated, losing their blood supply. Herniation of abdominal organs is present in 3–4% of people with abdominal trauma who present to a trauma center.

The primary concern in any splenic trauma is internal hemorrhage, though the exact amount of hemorrhage may be small or large, depending on the nature and degree of injury. Small or minor injuries often heal spontaneously, especially in children. Larger injuries hemorrhage extensively, often causing hemorrhagic shock. A splenic hematoma sometimes ruptures, usually in the first few days, although rupture can occur from hours to even months after 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.

Penile trauma can take several forms. Abrasions can be caused by a zipper injury, and fractures can be caused by sexual activity.

Brain damage may be caused by a number of factors, including fetal malformation due to genetic mutation or exposure to toxins, intrauterine hypoxia, or physical trauma during delivery.

Cerebral palsy is one example of brain damage incurred before or during delivery; about 10,000 children are diagnosed with cerebral palsy every year.

Bone fractures can occur during a difficult delivery. Fracture of the clavicle is the most common birth injury.