You don’t have to lie awake for hours past your bedtime to have insomnia. The condition manifests itself in several ways: trouble falling asleep (known as sleep-onset insomnia), staying asleep (sleep-maintaining insomnia), or waking up too early (early morning awakening).
Sleep specialists may also describe a sleep problem based on its underlying cause, such as a medical condition or a psychological issue. To do this they use the 11 classifications of insomnia below, developed by the American Academy of Sleep Medicine.
General insomnia is a classification of sleep disorders in which a person has trouble falling asleep, staying asleep, or waking up too early. These disorders may also be defined by an overall poor quality of sleep.
This disorder, also called acute insomnia or short-term insomnia, disturbs your sleep and usually stems from stress. The sleep problem ends when the source of stress is gone or when you adapt to the stress. The stress does not always come from a negative experience. Something positive can make you too excited to sleep well.
Behavioral insomnia of childhood
This disorder occurs when children don’t go to bed on time unless a parent or guardian enforces a bedtime. If the children are made to go to bed at a specified time, then they tend to fall asleep at a normal hour. If they are not given strict bedtimes, then they may linger awake for hours at night.
Idiopathic insomnia is a lifelong sleep disorder that starts during infancy or childhood and continues into adulthood. This insomnia cannot be explained by other causes. It is not a result of any of the following.
- Other sleep disorders
- Medical problems
- Psychiatric disorders
- Stressful events
- Medication use
- Other behaviors
It may result from an imbalance in your body, such as an overactive awakening system and/or an underactive sleep system, but the true cause of this disorder is still unclear.
Insomnia due to drug or substance
This type of insomnia is directly related to the use of any of the following substances.
- A food item
Your sleep is disrupted by your use of the substance. This type of sleep problem may also occur when you stop using a substance.
Insomnia due to medical condition
This type of insomnia is caused by another medical condition. It results in one or more of these problems.
- Difficulty falling asleep
- Waking often during the night
- An inability to return to sleep
- Worry about poor quality of sleep
This insomnia is a disorder only when it causes you distress or requires separate treatment.
Insomnia due to mental disorder
This insomnia is caused by a mental health disorder. The insomnia is a symptom of the disorder. The course and severity of insomnia are directly linked to that of the mental health disorder, but the insomnia is a separate focus of treatment. This insomnia is a disorder only if it is severe enough to require separate treatment.
Insomnia nonorganic, unspecified
This type of insomnia suggests that known substances and other physical causes of the insomnia have been ruled out. This means that the cause of insomnia is most likely due to an underlying mental health disorder, psychological factor, or sleep disruptive behaviors.
This name may also be used on a temporary basis while further evaluation and testing is completed. This is the name used when a person with insomnia does not meet the criteria for another type of insomnia.
Insomnia organic, unspecified
This type of insomnia is caused by a medical disorder, physical condition, or substance exposure. But the specific cause remains unclear. Further testing is required to discover the exact cause. This name may be used on a temporary basis while further evaluation and testing is completed.
Paradoxical insomnia is a complaint of severe insomnia. It occurs without objective evidence of any sleep disturbance. Daytime effects vary in severity, but they tend to be far less severe than one would expect given the expressed sleep complaints.
People with this disorder often report little or no sleep for one or more nights. They also describe having an intense awareness of the external environment or internal processes consistent with being awake. This awareness suggests a state of hyperarousal. A key feature is an overestimation of the time it takes them to fall asleep. They also underestimate their total sleep time.
Another feature is that the degree of sleep deprivation reported seems improbable. Their level of daytime functioning is likely to be only moderately impaired. Objective findings of fairly normal sleep duration and quality tend to result from an overnight sleep study. These findings are much different from their perception of poor quality sleep.
This insomnia is associated with excessive worrying, specifically focused on not being able to sleep. This insomnia may begin suddenly following an event or develop slowly over many years.
People with this sleep disorder worry too much about their insomnia and about being tired the next day. As a result they learn to become tense and anxious as bedtime approaches. They may have racing thoughts that all relate to insomnia and trying to fall asleep. As they worry about falling asleep, they become more and more tense, which makes it less likely that they will be able to fall asleep.
This tension and worrying about sleep increases through the night, setting up a cycle for ongoing insomnia. Even a simple bedtime routine may be a cue that causes tension to worsen. In fact, people with this insomnia may sleep better away from home. Focused and excessive worrying about sleep is the hallmark of this form of insomnia.