A panic attack is characterized by a sudden fear of disaster or losing control even when there is no danger. These can come on without any warning and can be exhausting and energy-draining. Physically, a panic attack can include difficulty breathing, sweating, nausea, hot flashes, nervousness, among other symptoms. Most people will never experience a panic attack or it may be very rare. If you consistently experience panic attacks and the feelings that come with them, you may have what is called panic disorder. Panic disorder is a type of anxiety disorder in which you constantly have panic attacks. It is not dangerous, but it can be very uncomfortable and lower the quality of your life if left untreated.