1, cell division and reproduction are limited. In old age, the generation of new cells is less than the death of aging cells, so the functions of all parts of the human body decline and it is easy to get sick and die.
There are good cells and bad cells in the human body, among which there is something called free radicals, which will make people aging. When you are young, there are many substances in your body that can fight against free radicals and keep you young, but in middle-aged and elderly people, free radicals increase and people get old.
3. People's nerves (nerve endings) will begin to shrink from middle age to old age, which is not conducive to cell reproduction and leads to a decrease in the number of new cells (similar to 1). When the value is 0, people will die.
4. Some scientists have suggested that the life expectancy is 1500 years, but urban pollution, food problems, nutrition problems, personal emotional problems and health problems ... are constantly shortening the life expectancy of human beings.
When we existed, death didn't come to us, but when we died, we were gone. If a person understands correctly, there is nothing to be afraid of when he stops living, and nothing to be afraid of when he is alive.
I think the following conclusion is the most perfect and scientific conclusion about "death"
Regarding death, the ancient Greek philosopher Epicurus once used this argument to counter the fear of death: "In yourself, I am used to the idea that death has nothing to do with us ... You should get used to believing that death has nothing to do with us, because all good and evil are in the feeling, and death is just the loss of feeling. For this reason, a correct understanding of death has nothing to do with us, which makes us happy with the fact that life has death. This understanding does not add endless time to life, but liberates us from the desire for eternal life. If a person correctly understands that there is nothing to be afraid of when he stops living, then there is nothing to be afraid of when he is alive ... So the most terrible of all evils-death-is insignificant to us, because when we exist, death has not come to us, and when we die, we are gone.
Death leaves great sorrow and pain to the living. Of course, the dead don't know or care, but the living realize its horror because of death. In other words, people die not for themselves, but for bystanders.
If a person correctly understands that there is nothing to be afraid of to terminate his existence, then there is nothing to be afraid of to live.