Final answer:
Stress is believed to contribute to up to 90% of all major illnesses. It can have negative consequences on both mental and physical health, leading to psychological disorders and physical illnesses. Negative interactions in relationships and high levels of work-related stress are also associated with health problems.
Step-by-step explanation:
Stress is believed to contribute to up to 90% of all major illnesses. When stress is extreme or chronic, it can have negative consequences on both our mental and physical health. For example, stress can contribute to the development of psychological disorders such as post-traumatic stress disorder and major depressive disorder, as well as physical illnesses like heart disease and common cold. Research has shown that negative interactions in relationships and high levels of work-related stress are also associated with health problems.