Sundowning, or sundown syndrome, affects some people who have Alzheimer's disease and dementia. People with dementia who "sundown" get confused and agitated as the sun goes down -- and sometimes through the night.
Sundowning may prevent people with dementia from sleeping well. It may also make them more likely to wander. Due to the stress it puts on caregivers, sundowning is a common cause of caregiver burnout.