When a person experiences stress, the brain responds by initiating 1400 different responses including the dumping of a variety of chemicals to our blood stream. This gives momentary boost to do whatever needs to be done to survive. If left unchecked, however, the person can have a heart attack or stroke.
Many people start drinking alcohol.
They get depressed, find it difficult to sleep, experience chest pain. The body runs out of the immunity to fight diseases. So, very often, these persons die of disease such as cancer, pneumonia, etc. The stress will never be identified as the cause of the death. I call the stress the proxy killer.