is the tension people feel when they are facing or enduring extraordinary demands, constraints, or opportunities and are uncertain about their ability to handle them effectively.

Stress

Explanation:

Stress is a tension that can be either mental or physical or both, and it is designed to help the body act in situations of danger or difficulty.

In this sense, stress can be helpful because it makes people more alert and decisive when dealing against a hostile enviroment.

However, stress reactions that last over very long period of time can be very damaging, both for mental and physical health, and this is because health professionals recommend different methods to handle stress in day-to-day life.

answer; no longer than a reasonable period of time;

an important point to remember about correlation is that while there is a _statistical_ relationship correlation does not equal _causation_

the first answer is: statistical

the second answer is: causation