The first influence is something external, like noise or bright light that hinders sleep. The second influence is any disorder, medication, or other substance that might be causing the sleep problem. Sleeplessness is considered to be a problem when it is severe enough to prevent the brain from getting enough rest on a consistent basis. An occasional sleepless night is not usually considered a problem. However, when sleeping problems last 2 weeks or more, the insomnia becomes more serious.
Insomnia can be a short-term problem.
If insomnia extends beyond 3 to 4 weeks, it is considered chronic. Insomnia can be caused by many factors, or a combination of factors. Methods to prevent insomnia are the same as those used to treat insomnia. The best prevention is to develop good sleep habits. Primary insomnia is diagnosed when difficulty falling asleep or staying asleep becomes a persistent problem.