Insomnia can exhibit itself in a number of ways, such as difficulty falling asleep, staying asleep or waking up too early, before you are ready to get up for the day.
There are three basic types of insomnia:
Transiet: Trouble sleeping for a few nights. Most everyone has experienced an episode of transient insomnia.
Short-term: Problems going to sleep or staying asleep for 2-3 weeks
Chronic: Insomnia or poor sleep that lasts 3 weeks or more