Agoraphobia:
This disorder can likely result from any of the other anxiety disorders because any of them can actually reach the level of becoming disabling to the sufferer. Panic attacks however, that are frequent enough to be termed "Panic Disorder", is probably the most common cause of agoraphobia. It is an avoidance behavior, that can become very restricting condition to the patient who has it.

Agoraphobia involves intense fear and anxiety of any place or situation where escape might be difficult, leading to avoidance of situations such as being alone outside of the home; traveling in a car, bus, or airplane; or being in a crowded area.

Approximately 1.8 million American adults age 18 and over, or about 0.8 percent of people in this age group in a given year, have agoraphobia without a history of panic disorder.

The median age of onset of agoraphobia is 20 years of age.

Some people with more advanced anxiety-avoidances, are termed "Agoraphobic". This is where the person reaches a point of actually being fearful of leaving their home, in order to avoid anxiety reactions to numerous things and places they have developed fears (phobias) of.

Agoraphobia ("fear of the marketplace"), is the condition, that restricts sufferers of anxiety to a severe extent, even causing them to be unable to leave their home, due to multiple anxiety responses to many things out in the world. This makes them disabled many times, from being able to work but what is worse, is that as with all anxiety disorders, it also restricts their enjoyment and pursuits in life!

Specific Phobia:
Specific phobia involves marked and persistent fear and avoidance of a specific object or situation.

Approximately 19.2 million American adults age 18 and over, or about 8.7 percent of people in this age group in a given year, have some type of specific phobia.

Specific phobia typically begins in childhood; the median age of onset is seven years.

Phobias, are fears of just about anything. There are the obvious ones that are more common, such as "fear of spiders" (arachnophobia) but there are the less-common ones as well, such as people who fear looking into mirrors etc... The list is extensive. All types of anxiety and phobias can be successfully treated with therapy and medications.