Nowadays, many people experience difficulties in sleeping as the demand to work harder and longer hour has become more prevalent. Sleeping difficulties not only occur to adult but also high school and University’s students as they are required to do assignments and studying overnight may lead to less hour in sleeping. This stressful condition may contribute to sleeping difficulty and transient insomnia, thus increasing the number of people who are suffering from insomnia. In 2011, Sleep Health Foundation has found that around 1 in 3 people have at least mild insomnia. This insomnia is characterized by the problem of staying asleep, early morning awakening and frequent nocturnal awakening at night. Stress condition such by work-related stress,…show more content… The 3P model includes three factors which are predisposing factors, precipitating factors and perpetuating factors. Predisposing factors refer to the factors that may increase the risk of having sleeping difficulties while precipitating factors includes life stress events that lead to sleep disturbance. Stress plays a key role in causing acute insomnia (Michael, 2015). Social factors, regards as predisposing factors, such as child-rearing which may disturb one’s normal sleeping schedule can increase the susceptibility to insomnia. Psychological factors, excessive worries for instances, may lead to a higher vulnerability on sleeping difficulties. Furthermore, stressful life events precipitate and trigger insomnia. Medical and psychiatric illness involving pains are examples showing that stimulus or arousal on the central nervous system can provoke the occurrence of insomnia (Erman, 2007). Contributing in both predisposing and precipitating factors, stress has shown a major role in gradually growing the risk of having sleeping problems and finally triggering insomnia as times go…show more content… First, experiments by Cano (as cited by Buysse et al., 2011) have shown that insomnia developed in stressed mice after the introduction of a stressor to them. This could apply even to humans, resulting in insomnia. Second, electroencephalogram studies of rats by Toth and Bhargava (2013) have shown the activation of brainstem regions and the other regions of arousal around the brain, in the event of a stressor. This would result in abnormal hormone secretion and would inhibit sleep in rats due to the increase in alertness. Finally, studies on Drosophila by Toth and Bhargava (2013) have shown that flies exposed to a stressor would be hyperactive, and sensitive; as compared to control flies. This would indicate that the flies would be unable to sleep due to the intense activity after the exposure to a stressor. Thus, studies on rats, mice, and fruit flies have shown that stress could be linked to sleep