A casualty, as a term in military usage, is a person in military service, combatant or non-combatant, who becomes unavailable for duty due to any of several circumstances, including death, injury, illness, capture or desertion.
In civilian usage, a casualty is a person who is killed, wounded or incapacitated by some event; the term is usually used to describe multiple deaths and injuries due to violent incidents or disasters. It is sometimes misunderstood to mean "fatalities", but non-fatal injuries are also casualties.
In military usage, a casualty is a person in service killed in action, killed by disease, diseased, disabled by injuries, disabled by psychological trauma, captured, deserted, or missing, but not someone who sustains injuries which do not prevent them from fighting. Any casualty is no longer available for the immediate battle or campaign, the major consideration in combat; the number of casualties is simply the number of members of a unit who are not available for duty. The word has been used in a military context since at least 1513. 
Civilian casualties are civilians killed or injured by military personnel or combatants, sometimes instead referred to by the euphemistic expression "collateral damage".
The military organisation NATO uses the following definitions:
In relation to personnel, any person who is lost to his organization by reason of being declared dead, wounded, diseased, detained, captured or missing. 
Any casualty incurred as the direct result of hostile action, sustained in combat or relating thereto, or sustained going to or returning from a combat mission. 
A person who is not a battle casualty, but who is lost to his organization by reason of disease or injury, including persons dying from disease or injury, or by reason of being missing where the absence does not appear to be voluntary or due to enemy action or to being interned.  
These definitions are popular among military historians.
In relation to personnel, any person killed in action, missing in action or who died of wounds or diseases before being evacuated to a medical installation.  
In relation to personnel, any person incapacitated by wounds sustained or diseases contracted in a combat zone, as well as any person admitted to a medical installation for treatment or recuperation for more than a day. There is a distinction between combat medical casualty and non-combat medical casualty. The former refers to a medical casualty that is a direct result of combat action; the latter refers to a medical casualty that is not a direct result of combat action.  
Civilian casualties refers to civilians that are killed or wounded as a direct result of military action.
A casualty classification generally used to describe any person killed by means of the action of hostile forces. 
A casualty classification generally used to describe any person reported missing during combat operations. They may have deserted, or may have been killed, wounded, or taken prisoner.
A casualty classification generally used to describe any person who has incurred an injury by means of action of hostile forces. 
A casualty classification generally used to describe any person captured and held in custody by hostile forces.
The word "casualty" has been used since 1844 in civilian life. 
According to WHO World health report 2004, deaths from intentional injuries (including war, violence, and suicide) were estimated to be 2.8% of all deaths.  In the same report, unintentional injury was estimated to be responsible for 6.2% of all deaths. 
The Purple Heart (PH) is a United States military decoration awarded in the name of the President to those wounded or killed while serving, on or after 5 April 1917, with the U.S. military. With its forerunner, the Badge of Military Merit, which took the form of a heart made of purple cloth, the Purple Heart is the oldest military award still given to U.S. military members. The National Purple Heart Hall of Honor is located in New Windsor, New York.
A Vietnam veteran is an individual who performed active military, naval, or air service in the Republic of Vietnam during the Vietnam War.
The total number of military and civilian casualties in World War I was about 40 million: estimates range from around 15 to 22 million deaths and about 23 million wounded military personnel, ranking it among the deadliest conflicts in human history.
Civilian casualties occur when civilians are killed or injured by non-civilians, mostly law enforcement officers, military personnel, rebel group forces, or terrorists. Under the law of war, it refers to civilians who perish or suffer wounds as a result of wartime acts. The term is generally applied to situations in which violence is committed in pursuit of political goals. During periods of armed conflict, there are structures, actors, and processes at a number of levels that affect the likelihood of violence against civilians.
World War II was the deadliest military conflict in history. An estimated total of 70–85 million people perished, or about 3% of the 2.3 billion (est.) people on Earth in 1940. Deaths directly caused by the war are estimated at 50–56 million, with an additional estimated 19–28 million deaths from war-related disease and famine. Civilian deaths totaled 50–55 million. Military deaths from all causes totaled 21–25 million, including deaths in captivity of about 5 million prisoners of war. More than half of the total number of casualties are accounted for by the dead of the Republic of China and of the Soviet Union. The tables below give a detailed country-by-country count of human losses. Statistics on the number of military wounded are included whenever available.
Killed in action (KIA) is a casualty classification generally used by militaries to describe the deaths of their own personnel at the hands of enemy or hostile forces at the moment of action. The United States Department of Defense, for example, says that those declared KIA did not need to have fired their weapons, but only to have been killed due to hostile attack. KIAs include those killed by friendly fire in the midst of combat, but not from incidents such as accidental vehicle crashes, murder or other non-hostile events or terrorism. KIA can be applied both to front-line combat troops and to naval, air and support troops. Someone who is killed in action during a particular event is denoted on Wikipedia with a † (dagger) beside their name to signify their death in that event or events.
Battlefield medicine, also called field surgery and later combat casualty care, is the treatment of wounded combatants and non-combatants in or near an area of combat. Civilian medicine has been greatly advanced by procedures that were first developed to treat the wounds inflicted during combat. With the advent of advanced procedures and medical technology, even polytrauma can be survivable in modern wars. Battlefield medicine is a category of military medicine.
Wounded in action (WIA) describes combatants who have been wounded while fighting in a combat zone during wartime, but have not been killed. Typically, it implies that they are temporarily or permanently incapable of bearing arms or continuing to fight. Generally, the Wounded in Action are far more numerous than those killed. Common combat injuries include second and third degree burns, broken bones, shrapnel wounds, brain injuries, spinal cord injuries, nerve damage, paralysis, loss of sight and hearing, post-traumatic stress disorder (PTSD), and limb loss.
Casualty evacuation, also known as CASEVAC or by the callsign Dustoff or colloquially Dust Off, is a military term for the emergency patient evacuation of casualties from a combat zone. Casevac can be done by both ground and air. "DUSTOFF" is the callsign specific to U.S. Army Air Ambulance units. CASEVACs by air today are almost exclusively done by helicopter, a practice begun on a small scale toward the end of World War II; before that, STOL aircraft, such as the Fieseler Fi 156 or Piper J-3 were used.
As of 4 September 2006, there have been 3,502 coalition deaths in Afghanistan as part of ongoing coalition operations since the invasion in 2001. In this total, the American figure is for deaths "In and Around Afghanistan" which, as defined by the United States Department of Defense, includes some deaths in Pakistan and Uzbekistan and the deaths of 18 CIA operatives.
Estimates of casualties of the Vietnam War vary widely. Estimates include both civilian and military deaths in North and South Vietnam, Laos, and Cambodia.
A combat medic, or healthcare specialist, is responsible for providing emergency medical treatment at a point of wounding in a combat or training environment, as well as primary care and health protection and evacuation from a point of injury or illness. Additionally, medics may also be responsible for the creation, oversight, and execution of long-term patient care plans in consultation with or in the absence of a readily-available physician or advanced practice provider. Combat medics may be used in hospitals and clinics, where they have the opportunity to work in additional roles such as operating medical and laboratory equipment and performing and assisting with procedures.
The casualties of the Napoleonic Wars (1803–1815), direct and indirect, are broken down below.
During the War in Afghanistan, according to the Costs of War Project the war killed 176,000 people in Afghanistan: 46,319 civilians, 69,095 military and police and at least 52,893 opposition fighters. However, the death toll is possibly higher due to unaccounted deaths by "disease, loss of access to food, water, infrastructure, and/or other indirect consequences of the war." According to the Uppsala Conflict Data Program, the conflict killed 212,191 people. The Cost of War project estimated in 2015 that the number who have died through indirect causes related to the war may be as high as 360,000 additional people based on a ratio of indirect to direct deaths in contemporary conflicts.
The number of Canadian Forces' fatalities resulting from Canadian military activities in Afghanistan is the largest for any single Canadian military mission since the Korean War between 1950 and 1953. A total of 159 Canadian Forces personnel have been killed in the war since 2002.
Grigoriy Fedotovich Krivosheyev was a Russian military historian and a Colonel General of the Russian military. He is mostly known in the West, via an alternative transliteration of his name, Krivosheev, as the editor of a book on Soviet military casualties in the 20th century, which was translated and published in English.
The term military medicine has a number of potential connotations. It may mean:
World War II losses of the Soviet Union from all related causes were about 27,000,000 both civilian and military, although exact figures are disputed. A figure of 20 million was considered official during the Soviet era. The post-Soviet government of Russia puts the Soviet war losses at 26.6 million, on the basis of the 1993 study by the Russian Academy of Sciences, including people dying as a result of effects of the war. This includes 8,668,400 military deaths as calculated by the Russian Ministry of Defence.
The Secretary of Defense Medal for the Defense of Freedom is a decoration established to acknowledge civilian employees of the United States Department of Defense (DoD) who are killed or wounded in the line of duty.
There were 2,456 United States military deaths in the War in Afghanistan. 1,932 of these deaths were the result of hostile action. 20,752 American servicemembers were also wounded in action during the war. In addition, 18 Central Intelligence Agency (CIA) operatives also died in Afghanistan. Further, there were 1,822 civilian contractor fatalities.
Military Medical Casualties are losses during wars of armed forces personnel on account of wounds or other effects received from various kinds of weapons, as well as those who are admitted to aid stations or medical installations for more than 24 hours. Military medical casualties are one category of battle casualties, which also include what are called irrecoverable losses—those already dead or who die of wounds before reaching an aid station, those missing in action, and those taken prisoner. Military medical casualties usually greatly exceed irrecoverable losses—for example, the ratio was about 4:1 in World War I and about 3:1 in World War II. A distinction is made between combat and noncombat military medical casualties. The former refers to casualties that are the result of wounds, trauma, burns, ionizing radiation contamination, poisoning, and frostbite; the latter refers to casualties that are the result of noncombat injuries and diseases not related to weapons.