Anxiety suffered by a person with a phobia can be experienced as both mental and physical symptoms.
Mentally, a person can become so worried about encountering or avoiding a particular situation that it can disrupt sleep, cause fatigue or irritability, or even make it difficult to concentrate on other matters.
Physically, anxiety in the face of fear can make a person sweat, breathe heavily, or experience irregular heartbeats (palpitations), dizziness, or faintness. Anxiety can also cause muscle pain or tension, and may even interfere with digestion, resulting in diarrhea, for instance.
Particular phobias are identified when the fear of - or exposure to - specific situations is so extreme that the person loses the ability to cope under those circumstances. A person's attempts to avoid such situations can become sufficiently disruptive to his or her life as to be debilitating.
Panic attacks can help lead to the development of certain phobias. Panic disorder is marked by recurrent, sudden, and extreme feelings of terror and panic (panic attacks) that is combined with persistent worry about having another attack, or changes in behaviour as a result of the attacks. A panic attack can cause a person's heart to pound and feel dizzy, faint, weak, or sweaty. Nausea, chest pains, a sense of unreality, and a loss of control often mark an episode, which can occur at any time, night or day. Panic disorder is not a phobia but an anxiety disorder. However, having a panic attack in an elevator can result in a fear of elevators or of confined spaces; fear of having attacks in public places may cause a person to avoid those places, leading to agoraphobia. Similarly, panic attacks can become symptoms of phobias, and may be triggered by exposure to the things or situations that people fear.
There are two types of social phobia. Generally, the phobia encompasses all social situations outside of family contact, and may be associated with low self-esteem and fear of criticism. Avoidance of social situations often leads to social isolation. Another type of social phobia may occur in people who are normally comfortable with informal social contact, but become excessively nervous, anxious, and flustered when they're the center of attention. This is likely to affect individuals who must perform or speak in public, even those who have considerable experience being in the spotlight (Sir Laurence Olivier developed "stage fright" at one period in his acting career).
Agoraphobia is typically associated with the lack of an easily available exit or escape route to a safe place (usually a person's home). People become frightened of being in public places, stores, or crowds, or of travelling alone, and are prone to panic attacks when they go out alone. The phobia may consist of a cluster of different fears that overlap, often resulting in people who are too frightened to leave the safety of their own homes. For this reason, agoraphobia is considered the most incapacitating of anxiety disorders.
Specific phobias generally develop in young adults and, if left untreated, persist for decades. When individuals are easily able to avoid the phobic situation, the impact of the phobia will not be as great. However, when a person has to go to great lengths to avoid certain situations, the phobia becomes disruptive to normal functioning. It's most important to get help. Treatment or therapy will enable a person to work and have an active social life.