Adjustment disorders are quite common in children and teens. They are characterized by an excessive reaction to stress.

People with generalized anxiety disorder worry about their finances, their health, their jobs, world events, and the future. Their worry is often out of proportion to reality.

A person with generalized anxiety disorder often worries excessively about health, money, family, or work, and continually anticipates disaster.

People who feel they're unable to regain control of their lives because of their responses to the trauma may have post-traumatic stress disorder.

Panic disorder is marked by chronic, repeated, and unexpected panic attacks—bouts of overwhelming fear of being in danger when there is no specific cause for the fear.

A phobia is an uncontrollable, irrational, and persistent fear of a specific object, situation, or activity. The fear experienced by people with phobias can be so great that some go to extreme lengths to avoid the source of their fear.

Most of us worry or get nervous every now and then. But, for people with anxiety disorders, these feelings occur all too often, and they may be overwhelming.

PTSD is a condition that often follows a terrifying physical or emotional event—causing the person who survived the event to have persistent, frightening thoughts and memories of the ordeal.

A growing number of scientific studies indicate that optimistic people tend to live longer and have better physical and mental health than pessimistic people.

When you're faced with a highly stressful event in your life, the strategies outlined here will help you cope.

No one can avoid all stress -- and a certain amount actually is good for you. But it's always best to keep unhealthy levels in check when possible.