The most common types of anxiety disorders are:

Separation Anxiety Disorder  - more typical in early childhood and characterized by excessive clinging to adult caretakers and reluctance to separate from them.

Generalized Anxiety Disorder - characterized by excessive worry/anxiety across a variety of situations that does not seem to be the result of identified causes.

Post-Traumatic Stress Disorder - historically associated with soldiers who have experienced combat; however, it may result from experiencing traumatic personal events (i.e. loss of a loved one, physical or sexual assault, or a natural disaster).  Symptoms may include:  anxiety; event flashbacks;  nightmares; and, reports of reliving the experience.

Social Phobia Disorder - characterized by excessive fear and anxiety about being in social situations (i.e. groups and crowds).

Obsessive-Compulsive Disorder - characterized by repetitive thoughts that are difficult to control (obsessions) or the uncontrollable need to repeat specific acts  or compulsions(i.e. hand washing or placing objects in the same arrangement).