Factors and Causes That Lead to Insomnia

Difficulty Sleeping Depends on Underlying Predisposition, Triggers

Understanding factors that contribute to insomnia including sleep drive, circadian rhythm, genetics, and other causes can lead to effective treatment
Understanding factors that contribute to insomnia including sleep drive, circadian rhythm, genetics, and other causes can lead to effective treatment. Tetra Images/Getty Images

It is 1 a.m. again. You can’t sleep. You have been lying awake for hours. Just when sleep seems within your grasp, you are cruelly pulled back to wakefulness. How are you going to function tomorrow? Why can’t you get to sleep? If you find yourself struggling to fall and stay asleep, learn how you can master the factors that lead to your insomnia and get the rest that you need. What factors lead to insomnia?

Consider sleep drive, circadian rhythms, genetics, and other contributing causes. Discover ways how you can finally get to sleep.

Sleep Depends on Drive and Circadian Rhythms

There are certain factors working in your favor that should help you get to sleep at night. When these are corrupted, however, they may quickly start working against you and lead to insomnia. To better understand how this may occur, it is important to first consider the patterns that lead to sleep and why some people can’t sleep at night.

Sleep depends on two independent processes: sleep drive and circadian rhythm. Sleep drive is the desire for sleep that builds gradually during wakefulness. Put simply, the longer you are awake, the more you want to sleep. This is thought to be due to the gradual accumulation of a chemical within the brain called adenosine, one of the neurotransmitters. Sleep is a time to clear adenosine away, and when you are awake it piles up and leads to increased sleepiness.

A poorly timed nap during the day will diffuse the chemical and diminish your ability to sleep at night.

The other factor that determines when (and whether) you can sleep is something called the circadian rhythm. Our bodies respond to the natural daily patterns of light and darkness, linking certain biological processes to these rhythms.

One of these processes is sleep.

There are certain factors that affect these circadian rhythms. Melatonin is a hormone that has a key role in regulating sleep patterns. Exposure to light exerts the most powerful influence, however. Taken together, the circadian rhythm encourages the specific timing of sleep and wakefulness. Sleep that is attempted counter to our natural desires is often ineffectual. Moreover, a prolonged shift in the timing of sleep may represent a circadian rhythm sleep disorder.

What Factors Cause Insomnia?

Insomnia is defined as difficulty falling asleep, staying asleep, or sleep that is simply not refreshing. How this happens is best understood by considering a theoretical model of what causes someone to have insomnia. According to Dr. Arthur Spielman’s model, there seem to be three considerations, summarized as predisposing, provocative, and precipitating factors.

First, it seems that some people have a predisposition towards insomnia. The threshold for developing insomnia will vary for each person.

Believe it or not, there are people who rarely or never develop trouble sleeping at night. On the other hand, some people may be unlucky and are simply predisposed to have insomnia. This likely relates to genetic factors (insomnia often runs in families), age, sex (more often women), substance use, and other medical and psychiatric conditions.

Insomnia may also be attributed to an increased alerting signal. This relates to the sympathetic nervous system, which is responsible for the so-called "fight or flight" response. Some people may have an increased sympathetic drive, meaning they are primed to respond to an external threat. This signal can keep you awake during the day – but it also keeps insomniacs up at night. Some have described this as being "tired but wired".

Even though you might have a predisposition towards insomnia, it has to be triggered. These triggers are called provocative factors. Insomnia might occur transiently and be secondary to stress, a cup of coffee, or an uncomfortable sleep environment. About 25 percent of people cannot identify the trigger for their insomnia. If you hadn’t encountered the trigger, however, you might continue to sleep without difficulty. Instead, you find yourself in the throes of acute insomnia. In time, this may resolve. But sometimes it doesn’t.

The final components that transform a passing difficulty sleeping into chronic insomnia are the precipitating factors. These are the elements that perpetuate the difficulty sleeping. These can best be understood by considering an example.

Let’s imagine that you lie awake several hours in the middle of the night, a common occurrence in insomnia. You recognize that you need 8 hours of sleep and by lying awake you are cutting into this time. You decide to start going to bed 2 hours earlier to compensate. This helps some, but now that you are going to bed extra early it is taking you more time to fall asleep. As you lie awake more of the night, your frustration increases and you compound your initial insomnia.

There are a variety of choices that might perpetuate your insomnia. Some people choose to limit their daytime activities because of sleepiness. This avoidance may reduce your physical activity. Since you aren't exercising, you may be less tired and unable to sleep. You may start working on your computer in bed to make the most of your time spent awake. The light from your computer and the activity may worsen your ability to sleep. In addition, you may start napping during the day to get some sleep, and this could undermine your sleep drive and ability to sleep at night. All told, perpetuating factors are going to prolong your battle with insomnia.

How to Finally Get to Sleep

Now that you understand the factors that might lead you to have difficulty sleeping at night, you no doubt wonder how you are going to get to sleep. In general, you can follow these simple rules:

  1. Build up your sleep drive through sleep restriction.

    Work to make yourself tired by limiting your time in bed with sleep restriction. Avoid naps that may diminish your ability to sleep at night. Do not sleep in divided periods. If you find you cannot sleep, do not allow yourself prolonged wakefulness in bed, but observe stimulus control. These interventions can increase the quality of your sleep.

  2. Respect your circadian rhythm, and sleep at the right time for you.

    Acknowledge your body’s desired timing of sleep. If you are a night owl, don’t go to bed too early and lie awake. If you wake early, allow yourself adequate sleep time by going to bed early as well. There are ways to adjust the timing of your sleep, but start by sleeping when your body desires.

  3. Avoid triggers that can precipitate insomnia.

    If you can identify the causes of your insomnia, do your best to avoid these triggers. Start by eliminating caffeine, especially after noon. Consider other ways that you may be ruining your sleep. Don’t forget about treating coexisting sleep disorders, as these can also trigger difficulty falling or staying asleep.

  4. For those with chronic insomnia, seek professional help.

    Finally, if you are suffering from chronic insomnia, lasting more than 3 months, you may need to seek professional help. When insomnia becomes prolonged, it is necessary to pursue other interventions. Sleeping pills may help in the short term, but other treatments are preferred for chronic insomnia. It can be very helpful to address the beliefs, thoughts, and feelings that surround your insomnia with a treatment called cognitive behavioral therapy.

If you suffer from insomnia, start by considering the factors that underlie your difficulty. Then talk with your doctor and if appropriate ask for a referral to a sleep specialist.


Kryger, MH et al. "Principles and Practice of Sleep Medicine." ExpertConsult, 5th edition, 2011.

Spielman AJ et al. "A behavioral perspective on insomnia treatment." Psychiatr Clin North Am. 1987;10(4):541-553.

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