Fear of death occurs in four situations: during old-age; during terminal or critical illnesses, or those requiring major surgery; during a variable time period before foreseen untimely death (some seconds or minutes in the case of accidents, or days or months during military combat, or months and sometimes years in prison confinement awaiting execution); and when such fear is by mental illnesses of various kinds.
Fears differ in kind physiologically and psychologically. Some fears of death trigger all instincts: for example, adrenalin flow, alarm, flight or fight syndrome, involuntary urination or bowel movement. Some prospects of death can be so frightening that they cause madness. Many people not only fear death itself, therefore, but the circumstance of death. In addition, while the circumstances of death may appear frightful for an individual, they may also appear frightful in respect to his or her dependents and loved ones, when under conditions that cause undue hardship and deprivation.
The fear of death is often associated with fear of the after-life (for believers). Some may dread ghastly punishment, believing themselves not to have been 'saved', or because they have committed great sins or crimes.
With extended lives and prolonged deaths becoming more common, a growing fear is of all that which now precedes dying for so many – the possibility of prolonged pain, the increasing weakness, the uncertainty, the loss of powers and chance of senility, and the sense of being a burden. This fear is further nourished by the loss of trust in health professionals (medical fraud and exploitative social practices, and having seen how dying friends and relatives were treated). The institutionalization and impersonality of dying also has increased. Trust which might have gone to a doctor or priest long known to the patient goes less easily to a team of strangers.
In all its forms, fear of death at the very least degrades human life, and at worst causes serious distortions in behaviour leading to insanity or crime, including the crime of homicide, killing to avert death.