This can affect a person's mood and attitude in a multitude of ways. Stress can make a person feel anxious or show symptoms of anxiety. This is especially serious in people who suffer from generalized anxiety disorder (GAD); GAD causes people to be anxious about every little thing in life. Another symptom of stress is irritability or hostility/anger. So, even though the individual may be a generally happy-go-lucky and easy-going person, stress can cause them to have an affected fight-or-flight response. This leads them to perceive even small things as a threat which can lead to exaggerated responses to stressors. Stress also manifests itself in thoughts. These thoughts may include self-criticism, difficulty concentrating, forgetfulness, and general mental distress