Difficulties falling asleep, nighttime awakenings, movements or bad dreams are signs of a restless night, but they do not necessarily have the same cause or solution. Restless sleep is more of an expression than a medical diagnosis, often used by patients to describe sleep that is not restful, somewhat fragmented during the night, with frequent awakenings, sometimes movements, and upon waking, the impression of having slept poorly. The feeling upon waking is as important as the course of the night. If fatigue, irritability or difficulty concentrating regularly return, it is better to look for what prevents having quality sleep. Difficulty falling asleep and repeated awakenings can correspond to insomnia. A night generally consists of four to six cycles of about 80 to 100 minutes, alternating between light sleep, deep slow sleep and paradoxical sleep. Brief periods of wakefulness between cycles are normal. In adults, at least seven hours of sleep are generally recommended, but a restorative sleep depends also on its quality and the feeling during the day, not only on its duration. Restless sleep and moving a lot at night can have various causes, including stress, anxiety, a change in routine, a noisy or too warm environment, temperature issues, time zone shifts and irregular schedules. Moving during the night does not necessarily mean that one is sleeping poorly or that one is not getting enough sleep cycles. However, if these movements are accompanied by repeated awakenings or fatigue during the day, they can sometimes reveal a sleep disorder. Involuntary movements, restless legs syndrome, parasomnia and other disorders that interfere with sleep can be underlying causes. Restless legs syndrome causes an urgent need to move the legs, usually in the evening, at rest. It can be accompanied by unpleasant sensations that interfere with falling asleep. Periodic limb movements occur during sleep: the person is not always aware of them, but their partner may notice repeated jerks. A parasomnia, such as sleepwalking or night terrors, can also be a cause. Nightmares can cause a sudden awakening, sometimes followed by difficulty falling back asleep due to a persistent state of alertness. Stress, a difficult period, lack of sleep can favor these bad dreams. If they repeat and cause fatigue during the day, it is useful to talk to a health professional. They must also be distinguished from night terrors: in the latter case, the person generally does not retain a specific memory of the episode. Difficulty falling asleep and nighttime awakenings can be symptoms of insomnia, which can also be manifested by fatigue or difficulty concentrating during the day. Alcohol can make us fall asleep but does not ensure good sleep, promoting more fragmented sleep during the night. It is better to avoid drinking three to four hours before bedtime. The evening cigarette can also delay falling asleep and fragment sleep, as nicotine stimulates the nervous system and promotes a state of wakefulness. Some psychostimulants prescribed for ADHD, such as methylphenidate, can cause difficulty falling asleep, especially depending on the time of the last dose. Some antidepressants can promote bad dreams as well as night sweats. Treatments prescribed for asthma or high blood pressure can also interfere with sleep in some people. If the nights change after the start of a treatment or a change in dosage, the prescriber can check the cause and, if necessary, adjust the dosage. Diet can also affect sleep. To calm nighttime agitation, it is recommended to regain regular landmarks: get up at a stable time; plan a calm moment before bedtime; practice regular physical activity during the day; make the room dark and quiet. Exposure to light during the day plays a role in the synchronization of the internal clock. It is recommended to favor outdoor environments during the day. Avoiding screens as much as possible before sleeping, generally within an hour before bedtime, is advised. Maintaining social interactions during the day and being active constitutes as many landmarks for the body. A relaxation technique can help slow the flow of thoughts at bedtime. However, these practical solutions do not replace the search for a cause when the nights remain difficult. Prolonged release melatonin has more convincing data in treating insomnia, but the benefit remains modest. It is better to consult before taking it, especially if one is already on a treatment. Having occasionally a bad night is not abnormal. Two criteria mainly attract attention: if it is frequent and there is an impact during the day, that is when one should wonder if there is not an underlying sleep disorder. Persistent fatigue, excessive sleepiness, difficulty concentrating, irritability, or memory problems can thus justify a medical opinion. A medical opinion is also important in cases of breathing pauses during the night; excessive sleepiness; unpleasant sensations in the legs; nighttime behaviors that expose to injury. Precisely describing what one feels (and what a bed partner observes) will help find the appropriate care. In case of persistent disturbances, it may also be useful to turn to the Morphée Network. Its questionnaire, intended for adults whose difficulties have lasted for more than three months, helps identify the most suitable health professional. In newborns, restless sleep is a normal phase: they can move, make facial expressions or make sounds without waking up. In older children, nightmares or night terrors can also disrupt the night. If a baby moves, observe him for a few moments: he may still be asleep. If he cries, check his needs and comfort him calmly. If the crying is unusual or if he seems to be in pain, seek medical advice. This phase evolves gradually during the first months, especially around 3 to 6 months. But this does not mean that all awakenings or movements cease at that age.