Several causes are proposed for<unk> -life<unk> : * Population heterogeneity (first proposed in ), is by far the most common explanation of<unk><unk> . Even if individual hazard rate follows a Gompertz law, if the population is heterogeneous, the population hazard rate may exhibit<unk> -life<unk> . * Redundancy exhaustion – in the reliability theory of aging, an organism's redundancy (reserves) are exhausted at extremely old ages, so every random hit results in death. In more detailed accounts, this only holds in relatively simple organisms – in more complex organisms with various subsystems,<unk>  is less present or entirely absent. * Less risky behavior and more sheltered environment for older people. * Various evolutionary explanations.
Late-life mortality deceleration
Fall prevention
Suicide prevention
Sex differences in stroke care
Sexually active life expectancy
Prevention of mental disorders
Therapeutic effect
Longevity