Good Stress and Bad Stress

The stress response (also called the fight or flight response) is critical during emergency situations, such as when a driver has to slam on the brakes to avoid an accident.

It can also be activated in a milder form at a time when the pressure's on but there's no actual danger — like stepping up to take the foul shot that could win the game, getting ready to go to a big dance, or sitting down for a final exam.

A little of this stress can help keep you on your toes, ready to rise to a challenge. And the nervous system quickly returns to its normal state, standing by to respond again when needed.

But stress doesn't always happen in response to things that are immediate or that are over quickly. Ongoing or long-term events, like coping with a divorce or moving to a new neighborhood or school, can cause stress, too.

Long-term stressful situations can produce a lasting, low-level stress that's hard on people. The nervous system senses continued pressure and may remain slightly activated and continue to pump out extra stress hormones over an extended period.

This can wear out the body's reserves, leave a person feeling depleted or overwhelmed, weaken the body's immune system, and cause other problems.