Dreamy Dwellings: How the Sleep Environment Affects Sleep Health in Adults—A Narrative Review

ABSTRACT Sufficient high‐quality, well‐timed sleep is essential to health and physical, cognitive and emotional functions. Historically, environmental factors such as threats from other beings have likely constrained sleep. Newer sources of sleep disruption include modern work schedules, climate change, light pollution and noise pollution. Influenced partly by these evolutionarily recent trends, clinical and subclinical sleep problems now affect billions of people. Furthermore, despite being readily amenable to improvements, there are instances in which the environment is not conducive to healthy sleep, precisely when bodily restoration is most needed, as in hospitals. This article reviews an array of environmental factors that affect sleep, including noise, light at night, use of screen‐based technology, temperature, ergonomics, olfactory stimuli, motion, the presence of other beings, sleeping in novel environments and the use of sleep‐monitoring devices. This is followed by a brief discussion of the potential of ‘smart’ sleep environments that attempt to enhance sleep by modifying conditions in the sleep environment in response to real‐time sleep data. We end with recommendations regarding practical options for improving the sleep environment as well as suggestions for future research.