Long-term, or chronic, stress affects our physical and psychological health, and can cause anxiety, insomnia, muscle pain, and a weakened immune system. It can also be a factor in heart disease and depression. Acute stress, on the other hand, is short-term: the stress you feel when your car breaks down, for example.
Acute stress can also be fun, like riding a roller coaster or skiing. Chronic stress is more damaging.