A complete guide to understanding insomnia, including what it is, how to identify it, what causes it, and how to treat it.

Insomnia is a tortuous but misunderstood condition. In this guide we’ll start from the very beginning and walk through everything you need to know about insomnia, from the basic building blocks all the way up to advanced techniques for treatment. We’ll cover what insomnia really is and how it’s different from other sleep disorders like apnea and narcolepsy; we’ll look at the most common causes of anxiety and how to identify whether or not you are suffering from it; we’ll talk about the most common and effective treatments for insomnia, including medication vs therapy; and we’ll correct some common misunderstandings about the consequences and effects of insomnia.


  1. What is Insomnia?
  2. What Causes Insomnia?
  3. What are the Symptoms of Insomnia?
  4. What are the Long-Term Effects of Insomnia?
  5. What are the Treatments for Insomnia?

What is Insomnia?

In it’s simplest form, insomnia can be defined as significant difficulty falling or staying asleep. People with insomnia desperately want to sleep better but feel as if they can’t. They often describe being awake for long stretches at night, taking a long time to fall asleep initially, feeling as if they haven’t slept at all, and anxiety or worry about sleep and it’s consequences.

Importantly, insomnia does not necessarily mean sleep deprived. In fact, most people with insomnia get sufficient sleep on a regular basis and on average only get 25 minutes less sleep than healthy sleepers without insomnia. Where people with insomnia do differ from the rest of the population is in terms of sleep efficiency and sleep anxiety.

People with insomnia almost always have poor sleep efficiency, meaning they spend too much time in bed relative to the amount of actual sleep they get. They also tend to think about and worry about their sleep and the potential negative consequences of not getting enough of it. More on both sleep efficiency and sleep anxiety later.

According to the most recent research, Insomnia is thought to occur in 10-20% of the population, is more common in women and older adults, and about half of the total number of cases are considered chronic. On average, sleep maintenance issues (trouble staying asleep) tend to be the most common type of insomnia symptom, and on average people with insomnia tend to underestimate the amount of sleep they get by up to an hour and a half.

It’s also important to understand that insomnia itself is a general term for difficulty sleeping, and while both professionals and lay people alike use the term casually with this general meaning, there is a technical definition and diagnostic criteria for insomnia.

Technical Definition of Insomnia and Diagnosis

According to the DSM-5, a diagnosis of primary insomnia requires that a person have difficulty with one or more of the following:

Additionally, the insomnia must:

With the official diagnostic criteria in mind, there are several important sub-types or classification of insomnia that are worth reviewing briefly.

Primary Insomnia vs Secondary Insomnia

Primary Insomnia is the term for insomnia that is unrelated to any other physical or mental health disorder. Primary insomnia is also sometimes called idiopathic insomnia (of unknown origin) or nonorganic insomnia (not caused by an organic physiological cause).

Secondary Insomnia, on the other hand, is when the insomnia is known to be caused by or directly related to another condition.

For example, someone who started abusing cocaine on a regular basis might well develop a difficulty falling and staying asleep. But because it was presumably caused by and maintained by the cocaine addiction, the insomnia would be thought of as secondary to the substance abuse problem. Similarly, other medical or mental health conditions such as hyperthyroidism, chronic pain, Parkinson’s Disease, anxiety, bipolar disorder, and depression can also cause and sustain insomnia. In situations like these when the insomnia is secondary, it’s often best thought of as a symptom or set of symptoms of another condition.

Lastly, insomnia is sometimes described as being co-morbid with another condition such as depression or diabetes. When two conditions are co-morbid, it simply means that they occur together, but there isn’t necessarily a direct causal connection between the two.

Paradoxical Insomnia

Paradoxical Insomnia is the term for a type of insomnia characterized by a high tendency to misperceiving sleep states as wakefulness. In other words, a person with paradoxical insomnia regularly describes getting little to no sleep at night; but when they are subjected to objective clinical recording of their sleep, they demonstrate largely normal sleep patterns in terms of both quality and quantity of sleep. Paradoxical Insomnia is also sometimes referred to as sleep state misperception, pseudoinsomnia, or sleep hypochondriasis.

Chronic vs Acute Insomnia

Sometimes a person’s insomnia is described as chronic, which means that it has been ongoing for some time, typically months or years at a relatively consistent intensity. If you’ve consistently had trouble falling asleep at night and going back to sleep when you wake up, and this has been the case for years, that might be termed chronic insomnia.

Alternatively, insomnia can be termed acute meaning that it was or has been of limited duration. If you recently went through a divorce and subsequently had a period of several weeks when you had trouble with your sleep, that could be termed acute insomnia.

Finally, Transient insomnia is sometimes used to refer to very brief episodes of difficulty sleeping, usually on the scale of days to a week. For example, many people experience transitory insomnia when adjusting to a new medication, sleeping in a new environment, or after traveling. Some healthcare providers will also use the term intermittent insomnia to describe a course of insomnia that waxes and wanes in intensity or even appearance—in other words, it comes and goes.

What Insomnia is Not (i.e. Other Sleep Disorders)

It’s helpful to be clear about other sleep disorders that are related to but distinct from insomnia. Below are brief descriptions of the most common non-insomnia sleep disorders:

What Causes Insomnia?

Insomnia is a complicated and in some ways poorly-defined condition, as evidenced from the discussion above. Similarly, the causes of insomnia are not nearly as well-defined and consistent as you might hope for. In this section we’ll take a look at the many factors that play a role in the development and maintenance of insomnia.

Direct Causes of Insomnia vs Predisposing Factors

When we talk about the causes of insomnia, it’s helpful to make a distinction between Direct Causes and Predisposing Factors.

Direct causes of insomnia are things that have a known direct effect on insomnia and poor sleep. Worrying about sleep and the anxiety that results directly suppresses the body’s need for sleep (Sleep Drive) and is therefore a direct cause of insomnia.

On the other hand, having an older age appears to predispose a person to developing insomnia, without knowing the reasons why that might be. It simply means that, statistically, a 70-year-old is more likely to have insomnia than a 20-year-old.

Finally, certain things could be both a direct cause and a predisposing factor. Female gender, for instance, predisposes a person to an increased risk for developing insomnia, although the actual relationship between gender and insomnia is unclear. It could be that hormonal changes associated with ovulation, menstruation, and/or menopause could all have direct physiological effects on sleep. On the other hand, women are, for example, more likely to be diagnosed with an anxiety disorder or need to breastfeed a child in the middle of the night, both of which affect sleep.

Initial Cause of Insomnia vs Sustaining Factors

Furthermore, what causes someone’s insomnia initially may not be the factor that most significantly sustains it in the present, and therefore may not be the best target of treatment. In other words, there’s an important distinction between an Initial Cause for insomnia and a Maintaining Factor of insomnia.

For instance, traveling and associated jet lag may initially cause insomnia, but over time bad sleep habits and anxiety about poor sleep may actually be the things that are most strongly contributing to the insomnia and therefore should be the primary focus of treatment.

Factors that may cause insomnia

With those distinctions in mind, below is a list of many of the most commonly known factors that can lead to insomnia or exacerbate insomnia. Note that many of the following causes of insomnia are also symptoms of insomnia.

What are the Symptoms of Insomnia?

Insomnia Symptom #1: Trouble falling sleep at night

Difficulty falling asleep at night—sometimes called initial insomnia or sleep latency—is one of the most common symptoms of insomnia. A common experience of those with insomnia is feeling like their mind “won’t shut off” or is “running a million miles an hour” while in bed waiting to fall asleep. More often than not, it results from 3 factors: a short or non-existent sleep runway, sleep effort (especially, sleep anxiety), or insufficient sleep drive.

  1. Sleep Runway. A sleep runway is a period of time before getting into bed that is relaxing and sleep promoting. It often involves reading, watching tv, stretching or meditating, or some other similarly non-arousing activity. Having a sleep runway routine is important because it gives your mind time to unwind from a long, active day and go into relaxation mode which is essential in order to fall asleep. Nobody goes from alert or aroused to sleepy; sleep only arrives through the doorway of relaxation.
  2. Sleep Effort. Sleep effort—any mental or physical act of trying to sleep—signals to your brain that it should go into a more aroused state and in the process inhibits your ability to sleep. Whether it’s counting sheep, preparing your favorite sleepy time tea, or doing deep breathing exercises, if it’s done with the intention of falling asleep, it will paradoxically wake you up and make it harder to fall asleep. Many people lay in bed unable to fall asleep because mentally they are trying to fall asleep, which is actually making it more difficult.
  3. Insufficient Sleep Drive. Sleep drive is the body’s need for deep, restorative sleep. It builds up over the course of the day and eventually crosses a threshold, at which point we become sleepy and then are able to fall asleep. However, when people get into bed before they are truly sleepy (which is very different than being “tired” or “exhausted”) they will remain awake and probably end up worrying about not falling asleep—which, consequently, not only wakes you up, but also conditions your brain to associate your bed with worry rather than sleep, making it that much harder to fall asleep the next time around.

Insomnia Symptom #2: Waking up during the middle of the night and having a hard time going back to sleep

It’s normal to wake up in the middle of the night. In fact, everyone wakes up at least several times throughout the night as a part of the normal sleep cycle even if they don’t remember it. People with insomnia may wake up many times throughout the night, but by far the biggest struggle is not being able to fall back to sleep after waking up, sometimes called middle insomnia.

Middle insomnia is usually the result of insufficient sleep drive and sleep anxiety. As we discussed earlier, sleep drive is your body’s need for deep sleep (technically stage 3 sleep). When we’re in deep sleep, we sleep very soundly and it’s actually difficult to be woken up. If you find yourself waking up frequently throughout the night, it may be because you’re not getting enough deep sleep. The solution often involves the use of a temporary course of sleep restriction to build up more sleep drive.

However the biggest culprit in middle insomnia is usually sleep anxiety. In other words, people wake up in the middle of the night and then start to worry about being up, not being able to fall back to sleep, or the consequences of not sleeping well. As a result, they begin to feel more aroused and anxious which makes it harder to fall back asleep. The most effective solution for sleep anxiety in the middle of the night is a collection of techniques called stimulus control that involve getting out of bed and doing something relaxing until you feel sleepy gain.

Insomnia Symptom #3: Waking up too early

Sometimes insomnia is characterized primarily by waking up too early, or what’s technically called terminal insomnia. Terminal insomnia can often be an indicator of poor sleep efficiency, meaning you’re spending too much time in bed and not enough time actually sleeping. However, terminal insomnia may also be a symptom of depression, so it’s worthwhile to assess for that possibility as well. Finally, some sleep medication, while helpful in getting you to fall asleep, may actually put an artificial ceiling on the duration of your sleep since processing the meds often interferes with your sleep cycles and could lead to waking up too soon.

Other Symptoms of Insomnia

Insomnia Self-Assessments

For more formal assessment tools for insomnia, the following is a brief selection of tools to better understand the extent to which someone may or may not have insomnia:

What are Long-term Effects of Insomnia?

First it’s important to remember the distinction between insomnia and sleep loss. Insomnia doesn’t not necessarily imply sleep loss, but rather, difficulty with sleep. As a result, what most people really want to know about is the long-term effects of sleep loss.1

While there’s been a lot of media coverage about how crucial it is to get at least eight hours of sleep per night and how dire the consequences can be if you don’t, a closer look at the research suggests much of this hand wringing about sleep is actually far overstated, primarily for two reasons:

Most of the research on the long-term effects of insomnia doesn’t do a very good job of disentangling the effects of insomnia specifically from other related conditions and issues such a stress, medical conditions, depression and anxiety, medication use, etc. The ones that do tend to show mild to non-existent effects. In other words, once you account for other lifestyle and medical factors, the chances of increased mortality or serious health consequences—even people with less than ideal sleep durations—is mild to none.

In general, 7 hours seems to be the amount of sleep associated with the least risk for long-term negative effects, although anywhere between 6 and 8 hours is considered normal my most sleep experts and contributes most to the many benefits of quality sleep.

In other words, as long as you’re not consistently getting less than 5.5 or 6 hours of sleep, you probably don’t have much to worry about in terms of long-term health consequences. In fact, the anxiety associated with worrying about the negative effects of poor sleep is probably doing more harm that your actual sleep.

All that being said, there important negative consequences to consistent very short sleep, including:

What are the Treatments for Insomnia?

Traditionally there have been two types of treatments for insomnia, psychological and pharmacological. Psychological treatments focus on modifying behavioral and mental habits that may be interfering with sleep, while pharmacological treatments use a variety of drugs to help people with insomnia fall and stay asleep. Most professional organizations and guidelines, including the American College of Physicians, recommend psychological treatments as first-line since they have generally been shown to be more effective and have fewer adverse effects compared to pharmacological treatments.

Psychological Treatments for Insomnia

Over the years there have been many psychological and behavioral approaches to insomnia that have been studied and implemented successfully for people suffering from insomnia. In the last 10 to 20 years, most of these techniques have been gathered under an umbrella treatment methodology called Cognitive Behavioral Therapy for Insomnia, and incorporated into one unified treatment.

Cognitive Behavioral Therapy for Insomnia (or CBT-I, for short) typically makes use of the following techniques and interventions:

Cognitive Behavioral Therapy for Insomnia is almost universally regarded as the best choice for the treatment of insomnia because it is the most effective, the beneficial effects persist even after treatment has concluded, and there are no known side effects.

Pharmacological Treatments for Insomnia

While there is a long history of prescribing medications as sleep aids, there are typically considered a second-line treatment because they lack demonstrated superior effects to other treatments, their effectiveness only persists as long as the medication is actively taken, and there are often serious short-term side effects and the long-term side effects are unknown. Most recommendations for the use of drugs to treat insomnia explicitly suggest limited and short-term use.

In general there are three categories of drugs for the treatment of insomnia, hypnotics, benzodiazepines, and antidepressants.

  1. There’s no evidence of any negative consequences on health or mortality from insomnia without sleep loss. ↩︎

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I appreciate it when you mentioned that sleep apnea is a condition when the person finds it hard to go to sleep or stay asleep even if they desperately try. My sister has been having that problem for a while now, and it is worrying because her lack of sleep is affecting her studies. She said that her brain won’t let her sleep at night no matter how much milk she drinks or how she tries to relax. Maybe this time, she needs to see a professional.

Logan, yeah with any kind of sleep difficulty is almost always a good idea to get a professional sleep study done to rule out apnea or get someone set up with a CPAP if apnea is present.

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