Sundowning and dementia

Sometimes a person with dementia will behave in ways that are difficult to understand in the late afternoon or early evening. This is known as 'Sundowning'.

What is sundowning?

Sometimes you might see changes in the person’s behaviour in the later afternoon or towards the end of the day. During this time the person may become intensely distressed, agitated and have hallucinations or delusions. This may continue into the night, making it hard for them to get enough sleep.

This is sometimes known as ‘sundowning’ but is not 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 stage and later stages.

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What causes sundowning?

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.

Some of these are related to the time of day, and others may happen at any time. Try to identify which of these problems might be affecting the person, as each problem may need a different treatment.

Tips for reducing sundowning

  • 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 seem agitated, try to calm them by distracting them, perhaps talking about a favourite memory or event they enjoy thinking about.
  • If they remain agitated, it could be that they have a need that is not being met. For more information see Communicating.
Read about other sleep problems

Get advice on other sleeping problems, as well as what support and care is available for a person with dementia and sleep disturbance.

Find out more
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