People with panic disorder are afraid of losing control of themselves. Frequently occurring panic attack symptoms are heart palpitations, sweating, shaking, nausea or dizziness, leading to thoughts of being about to faint, to die or go mad. Panic attacks often come completely unexpectedly and result in the fear of having another attack, and fear of the fear. Some people avoid situations in which an attack could happen, out of fear of having a panic attack. These can include queuing at the checkout, busy spaces, escalators or being seated in the heart of a theatre – essentially situations where they are afraid they cannot escape if they have a panic attack. If you avoid these or similar situations, you could be suffering from agoraphobia (a fear of public spaces).