A phobia is a type of anxiety disorder characterized by a persistent and excessive fear of a specific object or situation. Phobias are characterized by a sudden onset of fear and a duration of more than six months. Those affected will go to great lengths to avoid the situation or object, even if the risk is greater than the actual danger. They experience significant distress if the object or situation cannot be avoided. Other symptoms include fainting, which can occur in blood or injury phobias and panic attacks, which are common in agoraphobia. Approximately 75% of people who have phobias have multiple phobias.

Specific phobias, social phobias, and agoraphobia are the three types of phobias.

Phobias can be treated using a variety of techniques. Systematic desensitization, progressive relaxation, virtual reality, modeling, medication, and hypnotherapy are some of the techniques used. Psychologists and other researchers have developed effective behavioral, pharmacological, and technological interventions for the treatment of phobia over the last several decades.