Difficulty falling asleep is common to everyone and many of us experience nights when we cannot sleep, for example the night before an exam, the night before our wedding day, or when we have heard some bad news. In these situations, sleep difficulties are normal and they usually only last for a night or a very short period of time. However, there are people who regularly experience difficulties falling asleep, staying asleep or waking up early in the morning. As a result, these people experience feelings of fatigue and reduced daily performance. If a reoccurrence of this happens at least three times per week for a period of three months, this indicates that these people suffer from a sleep disorder called insomnia.