Delayed sleep phase syndrome is amongst the most common sleep disorder. The exact trigger through which it takes place has not yet been known. Most of the sleeping problems often occur at the adolescence age. More than 16% of the people today are facing sleeping disorder problem. Delayed sleep phase syndrome is often caused by the sleeping habits and lifestyle of a person. Especially teenagers, actors and late night shift workers are more prone to it. Also, habitual smokers and alcoholics have more chances to have disrupted circadian rhythm because of its harmful effects on body.