The following is a listing of definitions of the possible outcomes that may result from completing the Sleep Disorder Questionnaire.

Veuillez ajuster les définitions d’anglais en français en appuyant sur le sélecteur de langues à la partie supérieure gauche de l’écran. 

Daytime Sleepiness

Excessive daytime sleepiness is defined as difficulty staying awake or alert, or an increased desire to sleep during the day. The feelings of sleepiness may be stronger when you are sedentary, such as while driving or sitting at work. Although it’s normal to feel sleepy once in a while after going short on sleep, it’s considered excessive daytime sleepiness when this happens almost every day for at least three months.

It’s easy to confuse sleepiness with fatiuge, since both conditions are characterized by a lack of energy and may arise under similar circumstances, such as being awake for a long time. The principal difference is that people with fatigue may be unable to fall asleep despite feeling tired and sluggish. It is also possible to experience simultaneous fatigue and sleepiness.

Learn More


Insomnia is a sleep disorder that affects as many as 35% of adults. It is marked by problems getting to sleep, staying asleep through the night, and sleeping as long as you would like into the morning. It can have serious effects, leading to excessive daytime sleepiness, a higher risk of auto accidents, and widespread health effects from sleep deprivation.

Common causes of insomnia include stress, an irregular sleep schedule, poor sleeping habits, mental health disorders, like anxiety and depression, physical illnesses and pain, medications, neurological problems, and specific sleep disorders. For many people, a combination of these factors can initiate and exacerbate insomnia.

Learn More

Obstructive Sleep Apnea

Sleep apnea is a serious sleep disorder that happens when a person's breathing is interrupted during sleep. People with untreated sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times during the night.

If it’s not treated, sleep apnea can cause a number of health problems, including hypertension (high blood pressure), stroke, cardiomyopathy (enlargement of the muscle tissue of the heart), heart failure, diabetes and heart attacks. Untreated sleep apnea can also be responsible for job impairment, work-related accidents and motor vehicle crashes, as well as underachievement in school in children and adolescents.

Learn More

Mental Health Illness

Mental Illness includes a broad range of psychological or behavioural symptoms that reduce an individual’s capacity to cope with daily life; a person may lose contact with himself, his emotions may be uncontrolled, behaviour might be inappropriate, or a person might lose the ability to communicate effectively with other people.

There is no particular way to develop a mental illness. For some people it develops due to a chemical imbalance in the brain while, other causes may relate to the amount of stress in their lives, the patterns of communication they develop within their families, poverty and poor housing, the number of close friends and family they have to support them through difficulty and the degree to which each of them views their self-esteem. While it is difficult to determine why some people develop mental illness, research and education has enabled many to lead full and productive lives.

Learn More

Restless Leg Syndrome (RLS)

Restless legs syndrome (RLS) is a condition that causes an uncontrollable urge to move the legs, usually because of an uncomfortable sensation. It typically happens in the evening or nighttime hours when you're sitting or lying down. Moving eases the unpleasant feeling temporarily.

Restless legs syndrome, also known as Willis-Ekbom disease, can begin at any age and generally worsens as you age. It can disrupt sleep, which interferes with daily activities. Simple self-care steps and lifestyle changes may help relieve symptoms. Medications also help many people with RLS.

Learn More


Sleepwalking, sleep terrors, sleeptalking and sleep paralysis are some of the behavioural manifestations associated with the partial arousals from sleep known as parasomnias — a group of sleep disorders defined as undesirable physical events or experiences that occur during the initiation of sleep, during sleep or during arousal from sleep.1 Although more common in children, parasomnias can occur at any age.

During sleep, the brain cycles regularly between wakefulness, nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. Nonrapid eye movement sleep is subdivided into four stages: stage I, a transitional stage between wake and sleep; stage II, which makes up most of the sleep period; and stages III and IV, which typically occur in the first half of the night and during which more profound stimulus is required to wake the sleeper. Parasomnias occur when transitions between these stages are blurred (commonly between stages III/IV and the awake state), causing behaviours that lack the complete awareness and mentation associated with wakefulness.

Learn More

Circadian Rhythm Disorder (CRD)

Most people operate on a 24-hour biological clock that is synchronized with bodily hormone production and natural light and darkness. These 24-hour cycles are collectively known as the circadian rhythm, and they play a major role in our sleep cycle.

Circadian rhythm sleep disorders – formally known as circadian rhythm sleep-wake disorders – are a group of conditions tied to dysfunctions or misalignments with the body’s internal clock. Examples of these disorders include mild conditions such as jet lag, as well as more debilitating conditions such as delayed and advanced sleep-wake disorder, irregular sleep-wake rhythm disorder, and shift work disorder.

Learn More



1. Pacheco, D. (2022, March 25). Excessive Sleepiness. Sleep Foundation.

2. Suni, E. (2022, April 29). What Causes Insomnia? Sleep Foundation.

3. Cleveland Clinic. (2020, March 3). Sleep Apnea.

4. CMHA Durham. (2022, June 7). What is Mental Illness?

5. Mayo Clinic. (2022, June 7). Restless legs syndrome.

6. Fleetham, J.A. (2014, May 13). Parasomnias. CMAJ.

7. Pacheco, D. (2022, April 19). Circadian Rhythm Sleep Disorders. Sleep Foundation.