Why do people die?

Why do people die? Well this is a bit difficult question to answer. It is also complicated. But a medical explanation can be given to this question. Actually why do people die. Demarcation is like this. Even all the other organs are non functioning but the brain is functioning that person is not dead. But on the other hand even if all the other organs are functioning but the brain is non functioning that person is dead. But the actual question is the causation of brain death.
When there I a heart failure or a respiratory failure this can compromise the oxygen supply to the brain cells. If it lasts long enough it can cause irreversible brain cell damage and brain death. This may be the most common reason for brain death. But there are many other reasons. For an example a thrombus can occlude the artery supplying the respiratory center of the brain stem and which causes respiratory arrest. Ultimately this respiratory arrest can cause brain death. In some instances trauma can cause significant brain damage. Conditions like meningitis and encephalitis can ultimately damage the brain. At last to understand why do people die? Read more about legal death and brain death. You may need to read about persistent vegetative state.