The most common forms of anxiety disorders are general anxiety disorder, obsessive compulsive disorder, social phobia and other phobias, panic disorder and separation anxiety disorder.  These disorders are all attributable to past traumatic events or genetics, as most anxiety disorders are.  Very rare is it that anxiety problems appear for no apparent reason whatsoever, though some cases report it. 

On the other hand, the following forms of anxiety are not as often diagnosed as a disorder, because they are common worries that every one faces at some time or another.  This is not to say that a disorder cannot develop from such anxieties, because a phobia can be of practically anything object or situation. 

Existential Anxiety: This type of anxiety is related to spirituality and mortality, which is something everyone eventually faces.  Psychotherapy father Sigmund Freud referred to this type of worry as the “trauma of nonbeing.”  When a person comes to the realization that they are not immortal and will die someday this can fill them with great anxiety—particularly if they have ignored such realistic thoughts for a long period of time.

Religion, Freud believed, becomes a coping mechanism to put away this unwholesome fear of death.  The person then redefines death as merely a stage in existence, with an immortal soul being the next stage—so life will continue in some way, the anxiety ceases to be so intense.  Obviously, it would be easy for a person to develop obsessive compulsive disorder along with this existential form of anxiety.  This form of anxiety can be somewhat harmless and inspire creativity; but it can also be dangerous if a person begins to have strong suicidal urges due to feelings of hopelessness.  

Boredom Anxiety: This form of anxiety is much like it sounds—because of boredom in life, or a lack of meaning (similar to existential anxiety) a person may become bored of their present living situation.  They learn to create and develop anxieties for no apparent reason other than to have something to do.  The answer to treating this form of anxiety is obviously a form of tough love, which would be to separate the sufferer from the stressful distractions and try and find happier or more productive life.

Test And Math Anxiety: There is also believed to be a fear of tests and a fear of math that can develop in students.  This is natural since so much pressure is put upon students to succeed in academic achievements.  They may start to feel, especially at very young ages, that academic failure is associated with self worth, or that low grades will merit public embarrassment.  This bouts with anxiety can also lead to physical problems such as nausea, headaches and dizzy spells.  Such an anxiety attack over tests can actually hinder the performance of a student, who may otherwise be able to pass the exam.  Some debate exists whether test anxiety is an entity onto itself or just another form of agoraphobia. 

All forms of anxiety can lead to serious anxiety disorders and eventually emotional and physical problems.  It's best to confront the source of anxiety, even by professional evaluation if necessary, rather than just ignore the symptoms.