11/11/2025
This is such a regular occurrence so it's helpful to know why.
Sometimes a person with dementia may become intensely distressed and agitated in the later afternoon or towards the end of the day. This is known as ‘sundowning.’
The symptoms may continue into the night, making it hard for them to get enough sleep, but they aren’t necessarily linked to the sun setting, or limited to the end of the day.
Sundowning can happen at any stage of dementia but is more common during the middle and later stages.
The reasons why sundowning happens are not well understood, but it is possible that a range of different causes makes it more likely. These might include:
Tiredness, hunger, pain or other unmet physical needs
Not enough exposure to sunlight during the day
Overstimulation during the day, such as from a noisy or busy environment
Disturbance to the person’s ‘body clock’ caused by damage to the brain
Disturbed levels of hormones that vary over the course of the day
Sensory impairment, such as hearing or sight loss
Tiredness in other people causing the person with dementia to become upset
Mood disorders, such as anxiety or depression
Fewer carers around to look after the person (in a care home)
Side effects of prescribed drugs
Sometimes what seems like ‘sundowning’ could be the person trying to communicate a need. This could be needing the toilet, feeling hungry or being in pain.
Uneven indoor lighting and reflective surfaces can sometimes cause confusion by creating disturbing shadows or mirrors.
Close the curtains or blinds once it starts to get dark and cover the television with a dust cover, if it’s not being used.
Think whether something that’s happened during the day has affected them.
If they remain agitated, it could be that they have a need that is not being met.
If they seem agitated, try to calm them by distracting them, perhaps talking about a favourite memory.
[Image description:
A light blue infographic with the title 'What causes sundowning?' centred infront of a yellow glow, surrounding by eight different illustrations depicting each cause, including: tiredness, hunger, pain, lack of sunlight, overstimulation, sensory impairment, body clock disturbance, prescribed drug side effects, mood disorders, and hormone level imbalances.]