It can be transitory (30% of the population) or chronic (10% of the population) and is characterized by difficulty falling asleep, maintaining sleep or sometimes an early final awakening (well before the sunrise time expected) or a mixture of two or three of these, variable in time. Insomniacs will complain of one or more of the following; lack of energy during the day and / or cognitive difficulties (errors, difficulties of concentration, memory loss, ...), physical, social or behavioral limiting them in fields of activities such as work, family life and hobbies. The optimal treatment will be cognitive behavioral therapy for insomnia.
Respiratory disorders during sleep
This category is characterized by abnormal breathing during sleep and there are several types but the most known being obstructive sleep apnea and central apnea. Apneics will often complain of drowsiness, tiredness, frequent nocturnal awakenings (feeling of suffocation, need to urinate), dry mouth, headaches etc., but it is mainly the bed partner who will observe (or undergo !) snoring and respiratory stops during the night. Apneic patients will often have a medical history of high blood pressure, heart attack, stroke, type 2 diabetes, atrial fibrillation or coronary artery disease.
Again there are several disorders in this category but the best known is the restless legs syndrome (awake) and periodic movements of the legs during sleep. The first generally corresponds to an immediate need to move the legs associated with discomfort. The second occurs during sleep and people are generally not aware of it, even though they may significantly disturb sleep without the person's knowledge. The bed partner is again often the main witness. In this category, we also find bruxism (grinding of teeth) that can be recorded during a complete polysomnography. Bruxeurs will exhibit early tooth wear, increased sensitivity, and will also tend to tighten the jaw during the day. Jaw pain and headaches can result.
Hypersomnolence Disorders (narcolepsy, idiopathic hypersomnia)
It is primal to distinguish fatigue from drowsiness. Fatigue is a lack of energy whereas drowsiness is the sensation preceding the sleepiness (accompanied by yawning). This category describes disorders where people have excessive daytime sleepiness (the desire to sleep during the day) and tend to fall asleep during less stimulating activities (work, school, car, ...). Drowsiness affects many people in different spheres of their life (work, school, family, social network, ...). This category includes idiopathic hypersomnia and narcolepsy. Diagnosis is important to ensure safety and to help people regain their quality of life.
Parasomnias, Circadian rhythm disorders
Circadian disorders occur when an individual's internal clock is out of sync with the 24-hour day-night (light-darkness) rhythm of the earth. "Misalignment" can be caused for example by night work or jet lag. Some parasomnias will appear during childhood and will normally resolve to adulthood. In this way, the most well-known are somnambulism as well as nocturnal terrors.There is a multitude of other parasomnias, some of which occur during the dream period. This is the case of the TCSP (paradoxical sleep disorder) where the person will live, act then his dreams and consult after injuries.