In many legal jurisdictions, the manner of death is a determination, typically made by the coroner, medical examiner, police, or similar officials, and recorded as a vital statistic. Within the United States and the United Kingdom, a distinction is made between the cause of death, which is a specific disease or injury, versus manner of death, which is primarily a legal determination versus the mechanism of death (also called the mode of death) which does not explain why the person died or the underlying cause of death and can include cardiac arrest or exsanguination. Different categories are used in different jurisdictions, but manner of death determinations include everything from very broad categories like "natural" and "homicide" to specific manners like "traffic accident" or "gunshot wound". In some cases an autopsy is performed, either due to general legal requirements, because the medical cause of death is uncertain, upon the request of family members or guardians, or because the circumstances of death were suspicious.
International Classification of Disease (ICD) codes can be used to record manner and cause of death in a systematic way that makes it easy to compile statistics and more feasible to compare events across jurisdictions.
Terminology
Death by natural causes
A death by natural causes results from an illness and its complications or an internal malfunction of the body not directly caused by external forces, other than infectious disease. For example, a person dying from complications from pneumonia, diarrheal disease or HIV/AIDS (infections), cancer, stroke or heart disease (internal body malfunctions), or sudden organ failure would most likely be listed as having died from natural causes. "Death by natural causes" is sometimes used as a euphemism for "dying of old age", which is considered problematic as a cause of death (as opposed to a specific age-related disease); there are also many non-age-related causes of "natural" death, for legal manner-of-death purposes. (See .)
There is particular ambiguity around the classification of cardiac deaths triggered by a traumatic incident, such as in stress cardiomyopathy. Liability for a death classified as by natural causes may still be found if a proximate cause is established, as in the 1969 California case People v. Stamp.
Unnatural causes
An unnatural death results from an external cause, typically including homicides, suicides, accidents, medical errors, alcohol intoxications and drug overdoses. Jurisdictions differ in how they categorize and report unnatural deaths, including level of detail and whether they are considered a single category with subcategories, or separate top-level categories. There is no international standard on whether or how to classify a death as natural vs. unnatural.
"Mechanism of death" is sometimes used to refer to the proximate cause of death, which might differ from the cause that is used to classify the manner of death. For example, the proximate cause or mechanism of death might be brain ischemia (lack of blood flow to the brain), caused by a malignant neoplasm (cancer), in turn caused by a dose of ionizing radiation administered by a person with intent to kill or injure, leading to certification of the manner of death as "homicide".
The manner of death can be recorded as "undetermined" if there is not enough evidence to reach a firm conclusion. For example, the discovery of a partial human skeleton indicates a death, but might not provide enough evidence to determine a cause.
Categories by jurisdiction
United States
In the United States, a manner of death is expressed as belonging to one classification of a group of six possible: Natural Accident Suicide Homicide Undetermined Pending
In some jurisdictions, some more detailed manners may be reported in numbers broken out from the main four or five. For example: Legal intervention (e.g. capital punishment) Act of war Automobile accidents Deaths of prison inmates by acute intoxication