Long-term sleep impairment is related to an increased risk of somatic health problems, e.g. overweight, Type 2 diabe­tes, cardiovascular disease and premature death. Avoidance of caffeine, alcohol, energy-rich or fatty foods and light from computer screens close to bedtime may counteract impai­red sleep. A quiet, dark and well-tempered bedroom and physical activity during the day may have a positive impact on sleep. Impaired sleep may be related to stress and con­ditions at home or at work. Psychological sleep treatment is free of adverse side effects with effects comparable to effects of medical treatment.