Agoraphobia is often comorbid with panic disorder — meaning people often suffer from both conditions at the same time. It's an intense fear of not being able to escape whatever place you're in, and can often lead to an avoidance of leaving the house. People with agoraphobia can fear situations where this anxiety might flare up, and typically don't feel comfortable or safe in public, crowded places.
These attacks are a symptom of panic disorder, a type of anxiety disorder that affects some 2.4 million U.S. adults. The disorder most often begins during the late teens and early adulthood and strikes twice as many American women as men. No one knows what causes panic disorder, though researchers suspect a combination of biological and environmental factors, including family history (panic disorder seems to run in families), stressful life events, drug and alcohol abuse, and thinking patterns that exaggerate normal physical reactions.
Hyperventilation syndrome may occur when a person breathes from the chest, which can lead to overbreathing (exhaling excessive carbon dioxide in relation to the amount of oxygen in one's bloodstream). Hyperventilation syndrome can cause respiratory alkalosis and hypocapnia. This syndrome often involves prominent mouth breathing as well. This causes a cluster of symptoms, including rapid heart beat, dizziness, and lightheadedness, which can trigger panic attacks.
Occasional anxiety is an expected part of life. You might feel anxious when faced with a problem at work, before taking a test, or before making an important decision. But anxiety disorders involve more than temporary worry or fear. For a person with an anxiety disorder, the anxiety does not go away and can get worse over time. The symptoms can interfere with daily activities such as job performance, school work, and relationships.