Obsessive Compulsive Disorder (OCD) is a disorder in which people have thoughts they can’t get out of their minds (obsessions) or things they feel like they have to do, like rituals, counting or checking (compulsions). Many people have obsessions and compulsions; it is only considered a disorder if it interferes with you life or causes you marked distress.
With panic disorder, people experience frequent panic attacks. These are discrete periods of time in which people can feel like something terrible is going to happen, like they are having a heart attack. They may begin to avoid certain places or situations in an attempt to avoid experiencing the panic.
Phobias involve intense fear of specific things like heights, public speaking, taking tests, going over bridges, or being in enclosed places like elevators.
Post Traumatic Stress
Post Traumatic Stress Disorder can occur after a person has witnessed or experienced a potentially life threatening event. It is usually marked by reliving of the trauma, as well as by nightmares and intense anxiety.