One of the obvious causes of inability to sleep is work-related stress. In other words, employees that work round the clock without going on annual leave are more likely to be stressed and this would eventually lead to disturbed sleep patterns. To further illustrate this a study carried out by the University of Ibadan in 1998 in Lagos found out that 70% of employees suffer from mild to severe form of insomnia due to the stress attached to their jobs. Unfortunately, this is one of the reasons why some people lack good sleep at night.