Manner of death

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 codes are sometimes used to record manner and cause of death in a systematic way that makes it easy to compile statistics and feasible to compare events across jurisdictions.

Terminology

Natural causes of death

There is no single definition as to what constitutes death by natural causes. In the broadest sense, a natural cause of death occurs due to illness and its complications, or internal body malfunctions. Examples include pneumonia, diarrheal diseases, cancer, a stroke, heart disease, and sudden organ failure. Sometimes, infectious diseases are excluded from this definition. Whether a specific manner of death is considered "natural" depends on the deceased’s age, medical history, and specific context. As organisms age, various health-related consequences arise. In humans, a few examples include slower healing of skin tissue, thickening of blood vessel walls, and a less effective immune system. For example, a fall may be more likely to cause internal bleeding, plaque buildup becomes more likely to cause a heart attack, and a cold may be more likely to result in pneumonia.

Historically, most doctors had little to no understanding of medicine and as such attributed unknown causes to "old age." With modern medicine and medical machinery, it is possible to uncover true causes of death, though "old age" is still widely used for comforting loved ones.

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 of death

An unnatural cause of 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.