Daydreaming can become unhealthy. There is one disorder that can be found on http://www.dreammoods.com/dreaminformation/dreamtypes/daydreams4.htm. It is called  Von Munchausen's Disorder or Munchausen Syndrome. This is only labeled for children. The children with this disorder are inattentive in class and are found to have a faraway look in their eyes and sometimes open-mouthed snoring. They show withdrawal from class participation. This due to their constant daydreaming tendencies.  A normal person daydreams a average seventy to one hundred twenty minutes a day. But a person with this disorder the person daydreams alot more then this. Your daydreams aren't just random always though they can help you interpret your true feelings and help you in fulfilling your goal. This can be found on http://www.corbisimages.com/images/572/531C6D18-8C5C-47EF-92A8-7CAE0C7A1683/RF248811.jpg.   

A study done where one hundred and ninety-nine students participated, fifty-nine males and one hundred forty females,

How daydreaming works

 When you daydream what is occurring in the relaxed alpha state of brainwave frequency. In this state the subconscious mind is more receptive to suggestion. Alpha is the state people are in for effective meditation and creative visualization and is reached by getting to a state of calm relaxation. Many artists, writers and inventors report being inspired by ideas and images that came to them in the course of daydreaming. Athletes have long heralded visualization as a means to success. Many athletes report that daydreaming  or visualizing crossing finish lines, touchdowns and receiving gold medals before an event helps them to gather the confidence and energy that motivates them on to achieve that goal. All this can be found in Parthena Black's article Daydreaming. A research done by Eric Klinger in the 1980s revealed 3/4 of workers in "boring jobs" like driving a taxi or truck. He found his information by studying the same people over a certain amount of time and he would ask them about their lives in sessions and even watch them in their daily habitats to find how much they space out. This can be found on http://www.luciddreaming.com/information/daydreams.php.
      The function of daydreams is still unknown thus is the reason psychologists have not agreed on one definition. For now daydreaming is supposely a state of mind people go to to feel content and calm. The person who daydreams while in this state has a blank stare on the external apearance to those around them.

where daydreaming occurs

Recent studies done on January 2007 show that a network of regions in the brain's cortex are active when we daydream.  This was reported in the article Why we daydream. Although this is known it is still unknown why some people develop excessive daydreaming the lastest research on was by Cynthia Schupak and Jesse Rosenthal has been published. It's called Consciousness and Cognition.

                                             

What is daydreaming?

Daydreams are fantasies that people have that are not always connected to a person's current situation. They can be spontaneous and impusive thoughts, creations, or recallations of past experiences. Daydreaming is another type of  dreaming.  Daydreaming accesses the right side of your brain or the more creative side. This from the website http://library.thinkquest.org/CR0215422/daydreamingdreamweaver.htm 
 Although daydreams have been associated with laziness Psychologists Jerome L.Singer of Yale University and John S. Antrobus created a Imginal Processes Inventory, a daydream questionaire. Leonard Giambra and George Huba used this and found that the images of daydreams vary in three ways: how vivid or fun the daydreams are, how many guilt- or fear-filled daydreams they have, and how "deeply" into the daydream people go. This was found in 1960s. It was on http://en.wikipedia.org/wiki/Daydream.

Start of study of research on psychology

http://www.ic.arizona.edu/ic/psyc358/358-Lect_9.html

I went to this website and it shows tons of research done on daydreaming. One that caught my attention is Singer & Antrobus which in one study done 579 college students revealed that if the student is thinking positive the daydream is vivid, if guilty the daydream is dysphoric or dissatisfactic, and if anxious the daydream is distractible.