Medical Encyclopaedia › Insomnia (short definition)
In brief: Insomnia is present when falling asleep or staying asleep is disturbed over a longer period, or sleep is not restorative, so that daytime functioning suffers. If this lasts for at least three months, it is considered chronic.
Causes
Common triggers are stress, worries and stressful life events. In addition, there are unfavourable habits such as irregular sleeping times, screen use in bed, and caffeine or alcohol in the evening. Physical illnesses (pain, an overactive thyroid, restless legs syndrome, sleep apnoea), mental illnesses such as depression and medicines can also disturb sleep. Often, the fear of sleeping badly keeps the problem going.
Sleep hygiene
Helpful measures are fixed times for getting up and going to bed, a dark, quiet and cool bedroom, relaxing rituals in the evening, daylight and exercise during the day, and avoiding caffeine from the afternoon onwards and alcohol as a sleep aid. Anyone who cannot sleep should get up briefly rather than lie awake in bed for a long time.
Treatment
According to guidelines, the first choice for chronic insomnia is cognitive behavioural therapy for insomnia (CBT-I), which is also available as a digital health application. It includes sleep restriction, stimulus control and dealing with rumination, among other things. Sleeping pills such as benzodiazepines and Z-drugs should only be used for a short time, as they can be addictive. Herbal remedies such as valerian have weak evidence; melatonin is an option mainly for older people and for disorders of the sleep–wake rhythm.
When to see a doctor?
If sleep problems last longer than a few weeks, significantly impair how you feel during the day, or are accompanied by loud snoring with pauses in breathing, restless legs or low mood, medical advice is advisable – possibly with an examination in a sleep laboratory.
Related terms in the encyclopaedia
Sleep hygiene, Sleep medicine, Cognitive behavioural therapy, Melatonin, Valerian, Z-drugs, Benzodiazepines, Sleep apnoea, Polysomnography
Sources
- Deutsche Gesellschaft für Schlafforschung und Schlafmedizin (DGSM): S3-Leitlinie Insomnie bei Erwachsenen
- IQWiG: gesundheitsinformation.de – Gesundheitsinformationen des Instituts für Qualität und Wirtschaftlichkeit im Gesundheitswesen
Note: This article is for general information and does not replace advice, diagnosis or treatment from a doctor or pharmacist. Last updated: October 2026.