Stages of human death

[1] The academic study of death is called thanatology, a field pioneered by Élie Metchnikoff in the early 20th century.

Thanatology focuses on describing postmortem bodily modifications, as well as perspectives concerning psychosocial, medical, ethical, and spiritual aspects of death.

Prior to the 1980s, the legal standard defined death as the absence of cardiopulmonary function including the loss of all vital signs.

In the brain, this can be manifested by a hypoxic state which leads to cerebral edema and thus an increase in intracranial pressure.

[4] The aforementioned mechanism is the most common cause of brain death; however, this increase in intracranial pressure does not always occur due to an arrest in cardiopulmonary function.

A 5-stage process developed by Galloway and colleagues that is commonly used in forensic pathology is detailed below:[17][18] The postmortem interval (PMI) is also called the time since death.

[19] Below are some of the biochemical changes that happen during decomposition which can help estimate the time since death (keeping in mind that there is variation between species):[20] Techniques in veterinary medicine help estimate how long since bodies (animals such as pigs, dogs, rats, horses) have been dead.