More than 80 sleep disorders have been recognized, but a simple rubric exists for classifying symptoms. This system categorizes sleep disorders as problems initiating and maintaining sleep (insomnia); problems of too much sleep (hypersomnia, excessive sleepiness); circadian rhythm problems; and “things that go bump in the night” (parasomnias).
Insomnia is defined as a persistent difficulty falling or staying asleep and awakening earlier than desired despite adequate circumstances for sleep. Daytime symptoms such as fatigue, mood disturbance, difficulty with attention or memory, and behavioural problems, must be present. Short-term (or episodic) insomnia lasts less than three months and is usually triggered by acute medical illness or stress. In chronic insomnia, the sleep difficulty occurs more than three times a week for more than three months and is not better explained by another sleep disorder (American Academy of Sleep Medicine, 2014). If left untreated, chronic insomnia can last for decades.
Excessive daytime sleepiness is characterized by a complaint of constant or recurrent daytime sleepiness, typically with inappropriate sleep episodes.
Screening for insomnia
Athens Insomnia Scale
A screening tool for assessing the sleep quality of a patient.
If the patient scores higher than 10 on the Athens Insomnia Scale, assess the areas described below.
Sleep Schedule and Sleep Hygiene
Collect information on bedtimes, the time it takes the patient to fall asleep, the number and duration of nighttime awakenings, the final awakening in the morning, the time the patient gets out of bed and the difference between weeknight and weekend sleep schedules and sleep quality.
Ask about the patient’s beliefs in terms of sleep need and about coping or compensatory behaviours, including excessive time in bed and use of hypnotics. Learn about the patient’s bedtime routine and any disturbing factors in the sleep environment, such as electronic devices, disruptive partners, ambient noise, room temperatures and darkness.
Anxiety or Worry at Night
Ask the patient about anxiety, worry, frustration, problem solving, rumination about stressful issues, and the inability to “switch off” before bedtime or when lying awake in bed at night.
Assess daytime sleepiness, mental and physical fatigue and problems with concentration and memory, and inquire about mood and irritability. Daytime sleepiness is usually not the leading daytime symptom of insomnia; patients with insomnia more often complain about mental exhaustion and an inability to nap during the day.
Psychiatric and Physical Disorders
Screen for specific sleep disorders and for physical and psychiatric conditions that may contribute to insomnia (see “Insomnia” section on facing page).
Review medications that have a CNS-stimulating effect or that disrupt sleep (e.g., diuretics).
Inquire about caffeine and other substance use, and consider the effects of alcohol withdrawal on sleep.
Screening for excessive daytime sleepiness
The most common daytime symptoms of sleep disorders are daytime sleepiness and fatigue.
All patients with excessive daytime sleepiness must be assessed for inattention or sleepiness when driving, and for accidents or near-miss accidents related to driver sleepiness.
All patients who are tired, sleepy or fatigued should be screened for sleep apnea.