Sundowning is documented as something that is known to happen, but it is not well understood why it happens and what the triggers are. What has been noted, is that there has been a big increase in the occurrence of sundowning in the recent really hot weather, which results in an increase in the search terms.
Sundowning is a change of behaviour that happens usually between the hours of 3pm-9pm, but can go on later and within those hours can last for a couple of hours or all of them. It all depends on the particular person. Exactly how the change of behaviour presents, again will be specific to the person. It generally displays as agitated behaviour, which might mean that someone is more aggressive, or it might mean that they start to pace and wander around their environment, with what looks like no particular intention. Or they might wander in the attempt of trying to find a way out, so they can wander in the streets. They may start shouting in their agitation or hit out to anyone who approaches them in a way that they do not like.
There has been some research into sundowning, what is known is that it occurs and can be challenging to manage at times, but again, if someone is happy pacing around and it does not other cause disruption in the environment, then the impact on others is not huge. The underlying reasons behind it are not well understood, but there is some anti-anxiety medication that can assist with some of the symptoms. However some medications to reduce anxiety symptoms can make the person sleepier and therefore creates an increased falls risk. Medication should be taken with medical advice, and the side effects should be discussed with the doctor or other prescriber.
The incidence of sundowning has increased with the hot weather, particularly with the very hot spell in the UK in early August. This temperature change will have affected everyone, as people are at greater risk of heat stroke and/or dehydration. Again, the link to temperature and sundowning is noted, but not well understood.
Sundowning does not happen to everyone who has dementia, but is not uncommon and the particular presentation will be specific to that person. Therefore how the sundowning presents will need to be carefully managed so that the person with dementia and those people around them are safe or as safe as is possible to achieve. And now with the climate change and the likelihood of further episodes of extreme heat happening in the future, care should be taken to plan around an increase in symptoms of incidence of sundowning in hot periods.
If this affects you, I have help and advice in my book, Compassion with Dementia on lots of different aspects of presentation that affects people with dementia: https://tinyurl.com/39hta4a6