Examples of mental stress are high responsibility, long hours, perfectionism, anxiety, and worry. Present-day reasons for increased stress are: rapid and disturbing changes due to modern science and technology; education that creates a spirit of competition and rivalry; the great expansion of cities; the change in values and lifestyles; the break-up of family life and loss of faith and love in mutual relations. This stress or build-up of mental tension does not only result in a lack of peacefulness but causes many physical and mental diseases such as: high blood pressure, insomnia, indigestion, asthmatic ailments, peptic ulcers, heart attacks and even cancer. It lowers man's immunity to diseases and accelerates the process of ageing.
Academic researchers have shown direct evidence that prolonged exposure to stress can accelerate the aging of brain cells and lead to impairment of learning and memory. Abnormally high levels of stress hormones, such as adrenalin, damaged brain cells (of rats) and in humans may be linked to Alzheimer's disease by affecting the cells of the hippocampus region of the brain.