Sundowning is a term broadly used to describe a set of behaviours occurring in people with or without dementia, which commonly presents later in the afternoon, evening and late at night. Behaviours include confusion, disorientation, anxiety, agitation, yelling and calling out, aggressive outbursts (verbal and/or physical), pacing and wandering.

While not a formal psychiatric diagnosis, the prevalence of sundowning is well recognised and well documented. Some literature suggests rates of sundowning for elderly persons with cognitive impairment such as dementia are as high as 66%. Sundowning can be very challenging to manage and have a significant impact on the person and their loved ones/carers who are supporting them.