A single phobia is a focused fear of certain things, animals or situations. The fear can be accompanied by intense psychical symptoms and panic. The person in question usually knows well that his fear is not real, but the fear defeats common sense. Common phobias are fear of heights, fear of flying, claustrophobia, fear of the dentist, fear of spiders and fear of mice. A single phobia is almost always accompanied by avoidance behavior, or the situation is endured with great fear.