Insomnia can be caused by a number of factors, from psychological issues to physical ailments. And because there are so many different causes of insomnia, it can be difficult to get to the root of the problem without first consulting a doctor. The sources of this widespread sleep disorder can be grouped into a few categories.
Psychological conditions: Depression, anxiety, bipolar disorder, post-traumatic stress disorder (PTSD) and obsessive compulsive disorder (OCD). Such conditions are fall into the category of mental illness or mental disorders, but the psychological issues that lead to insomnia aren't always that severe. Everyone has had experiences with stress, tension, fear and anxiety, any of which can result in insomnia.
Drugs: It's no surprise that drugs can cause sleeplessness. Any sort of stimulant that you take can effect your brain and disrupt your ability to get enough sleep. No doubt you've had trouble falling asleep on nights when you drank too much coffee or other caffeine-loaded drinks. One of the major causes of long restless nights is too much caffeine. Other stimulants that can interfere with a regular sleep cycle are cocaine, amphetamines, various herbs, ephedrine, taurine, and methamphetamine.
Environmental changes: Many people are accustomed to a regular nightly routine and a particular set of circumstances which must be in place in order to get a god night's sleep. Any alteration of this routine can upset the physical and emotional balance and lead to a sleepless night. Travelers often complain of this, and it's one of the primary sources of jet lag. But you don't have to leave town, or even your room, to be affected by this. Sometimes it's minor changes that disturb people most: a new pillow or leaving the TV on may be enough to keep someone awake through the night.
While these are some of the most common reasons for insomnia, this problem has many causes. If you have trouble getting to sleep at night, one of the reasons listed here may be the culprit.