Sundowning: Symptoms, Causes and How to Help

If you care for someone with dementia, you may have noticed that the late afternoon and early evening bring a particular kind of difficulty. The person you love seems more confused, more agitated, or more distressed than they were just hours before. They may ask to go home even though they are already there. They may pace, call out, or seem frightened by something you cannot see. And you are left trying to understand why.

This pattern has a name: sundowning. It is one of the most challenging aspects of dementia care, and it is experienced by carers across the country every day. Understanding what is happening, and why, can make a real difference to how you respond.

What is sundowning in dementia?

Sundowning is a term used to describe a worsening of confusion, anxiety, agitation and behavioural disturbance that typically occurs in the late afternoon or early evening in people living with dementia. It is not a separate disease or formal diagnosis, but a cluster of symptoms that many people with dementia experience at a particular time of day.

According to Dementia UK, sundowning is thought to affect around 20% of people with dementia living in the community. In residential care settings, that figure rises to approximately 80%, particularly when a person has recently moved or changed rooms. It is most common during the middle and later stages of dementia.

The term “sundowning” suggests a link to the setting sun, and while the timing is often associated with dusk, symptoms can begin as early as 3pm and, in some cases, continue well into the night.

Why does sundowning happen?

The causes of sundowning are not fully understood, and in most cases multiple factors are involved. Research points to a combination of neurological changes, biological disruptions and environmental influences.

Circadian rhythm disruption

At the centre of sundowning is a breakdown in the brain’s internal body clock. This clock is regulated by a small structure deep in the brain called the suprachiasmatic nucleus (SCN). In Alzheimer’s disease and other forms of dementia, the SCN undergoes neurodegeneration and neurofibrillary degeneration, causing the circadian rhythm to flatten. Instead of experiencing a clear cycle of wakefulness and rest, the person with dementia experiences similar levels of alertness across both day and night. This biological disruption, combined with cognitive and emotional changes, is considered a key driver of sundowning (Reimus and Sieminski, Journal of Clinical Medicine, 2025).

Melatonin decline and pineal gland calcification

Melatonin is the hormone that prepares the body for sleep. In Alzheimer’s disease, the pineal gland, which produces melatonin, undergoes progressive calcification. This significantly reduces melatonin levels and disrupts the brain’s ability to signal that night time is approaching. Without that hormonal cue, a person may become hyperactive or distressed in the evening hours, leading to the wandering, agitation and confusion that characterise sundowning.

Unmet needs and environmental triggers

Beyond the neurological changes, sundowning is frequently made worse by factors that are more amenable to intervention. Common triggers include:

• Tiredness built up over the course of the day
• Hunger, thirst or pain that the person cannot easily communicate
• Low or changing light levels, which can create confusing shadows and reduce visual clarity
• Overstimulation during the day, such as noise or a busy environment
• Environmental change, including moving to a new room or care setting
• Reduced staffing or carer presence in the early evening
• Side effects from certain medications, particularly those with a sedative or anticholinergic profile
• Mood disorders, including anxiety and depression, which are common in people living with dementia

The Alzheimer’s Society notes that sensory impairments, including hearing or sight loss, can also contribute, as can the visible tiredness of those around the person with dementia.

What does sundowning look like?

The symptoms of sundowning are an intensification of behaviours that may already be present during the day. What changes is their severity, their timing and, crucially, the distress they cause.

Confusion and disorientation

The person may become convinced they are in the wrong place, even when at home. They may insist they need to “go home”, believing themselves to be somewhere unfamiliar. They may think they need to collect children from school, go to work, or fulfil a responsibility that belongs to an earlier chapter of their life. Repeated questioning is common.

Agitation and restlessness

The person may pace, fidget, pull at their clothing, or attempt to leave the house. This behaviour is rarely aimless. It often reflects an unmet need, a fear, or a purpose that feels entirely real to them.

Anxiety and distress

Sundowning typically produces intense feelings of fear and unsettledness. The person may cling to a familiar carer, become tearful or call out for reassurance. From the outside, this can look like challenging behaviour. From the inside, it is genuine terror.

Hallucinations and paranoia

In some cases, the person may see or hear things that are not there, or develop paranoid beliefs about the people around them. The Alzheimer’s Association notes that low lighting can worsen this by creating shadows that are misinterpreted as threatening shapes or figures.

Who is most likely to experience sundowning?

Sundowning can occur at any stage of dementia and with any type, though it becomes more common as the condition progresses. There is no firm evidence that it is more prevalent in one form of dementia than another, although it is most frequently reported during the middle and later stages.

Research suggests a possible link between carrying the APOE epsilon-4 gene variant, a known risk factor for Alzheimer’s disease, and a higher likelihood of experiencing sundowning. However, the relationship is complex and sundowning remains a poorly defined phenomenon in clinical terms, with reported prevalence rates across different studies ranging widely.

What is consistently reported across the research is that the burden on carers is significant. Sundowning is one of the most common reasons for the placement of a person with dementia into residential care, placing enormous strain on family carers who are already exhausted.

How to help with sundowning

There is no single solution, but a combination of consistent strategies can significantly reduce the frequency and intensity of episodes.

Build a calm and structured evening routine

Consistency is one of the most effective tools available to carers. Predictable mealtimes, familiar activities and a regular bedtime help to anchor the person with dementia in the rhythm of the day. Where possible, schedule more stimulating activities for the morning hours and keep evenings quieter and less busy.

Manage the environment carefully

Close curtains or blinds before dusk to reduce visual cues that darkness is falling and to eliminate confusing reflections. Ensure the home or room is well lit in the early evening to minimise shadows. Turn down noise from televisions and busy environments. If the person is in a care home, a consistent evening environment, with familiar staff and settled routines, matters enormously.

Dementia UK recommends displaying a dementia clock that shows the day, date and time of day. This can help orientate a person who becomes confused about where they are in time.

Support daytime activity and natural light

Time spent outdoors in natural daylight helps to regulate the body’s circadian rhythm. A 2022 meta-analysis cited by Reimus and Sieminski (2025) found that both inadequate natural light during the day and dim indoor lighting in care home environments were independently associated with greater agitation, anxiety and other sundowning symptoms. Where going outside is not possible, positioning the person’s chair by a window can provide meaningful light exposure.

Regular physical activity during the day, even gentle walking, has also been shown to reduce evening restlessness. One study found that people with dementia who walked for at least 120 minutes per week with their carers showed significant improvements in the frequency and intensity of sundowning symptoms, particularly when walks took place in the afternoon.

Communicate calmly and with patience

During an episode, approach the person gently and at their level. Speak slowly and in short sentences. Ask what they need and listen carefully. Gentle physical reassurance, such as holding their hand or sitting close beside them, can ease distress considerably. Avoid arguing or correcting them, as this almost always increases anxiety rather than resolving it.

Distraction can be highly effective. Moving to a different room, offering a warm drink or a small snack, playing a familiar piece of music or looking through old photographs can redirect the person’s attention and help calm a difficult moment.

When to speak to a GP or specialist

If sundowning is causing significant distress or putting the person at risk of harm, speak to the GP or a specialist. A thorough assessment can rule out treatable physical causes such as a urinary tract infection, unmanaged pain, restless legs syndrome or poorly managed depression, all of which can worsen or closely mimic sundowning.

For a broader guide to supporting someone through the day-to-day realities of living with dementia, see our Caring for Someone with Dementia: A Practical Guide.

Medications and sundowning: what carers need to know

Most clinical guidance recommends non-pharmacological approaches as the first line of response. When medication is considered, it is typically prescribed for a specific co-existing condition, such as depression, anxiety or insomnia, rather than for sundowning itself.

Carers should be aware of the risks associated with certain sleep-inducing drugs, particularly the class known as Z-drugs (including zopiclone and zolpidem). A large population-based study drawing on data from over 27,000 people living with dementia in the United Kingdom found that Z-drug use was associated with a significantly increased risk of falls, fractures and strokes (Richardson et al., BMC Medicine, 2020). These risks are serious, and any decision to prescribe them should always involve a careful and individualised assessment.

If medication is under consideration, melatonin is sometimes used to support circadian rhythm regulation. Evidence for its specific effectiveness in reducing sundowning is mixed, but it has shown some benefit for sleep quality and cognitive function in mild to moderate Alzheimer’s disease, with a low risk of side effects.

The consistent finding across the research is that behavioural and environmental interventions, while requiring greater carer involvement, tend to be more effective than pharmacological approaches and carry far fewer risks.

Sundowning in care homes

Care homes present both particular challenges and particular opportunities when it comes to sundowning. The move into residential care is can itself be a trigger; a new and unfamiliar environment can intensify disorientation in the evenings, particularly in the weeks immediately after admission.

Good dementia care environments are designed with this in mind. Consistent staffing in the early evening, well-lit communal spaces, structured activities that wind down gradually, and care staff trained to recognise and respond to sundowning with compassion rather than correction all make a meaningful difference.

For families, visiting in the late afternoon and early evening can provide vital continuity for a person with dementia who is struggling to orientate themselves. A familiar face during a difficult hour carries real weight.

Frequently asked questions

What time does sundowning usually start? Sundowning typically begins in the late afternoon, often around 4pm to 5pm, and can continue into the evening or early night. It may start later in summer months when daylight hours are longer, and earlier in the darker months of winter.

Is sundowning the same every day? No. Sundowning does not follow a perfectly predictable pattern. A person may experience it on some days but not others, and its severity can vary considerably. Keeping a brief diary of triggers and patterns can help carers identify what makes episodes more or less likely.

Does every person with dementia experience sundowning? No. Not everyone with dementia will experience sundowning. It is more likely in the middle and later stages of the condition, but it is not inevitable. A person affected by sundowning will not necessarily experience it every evening.

Can sundowning be caused by something physical? Yes. Unmet physical needs, including pain, hunger, dehydration, a urinary tract infection or constipation, can trigger or worsen sundowning. If sundowning appears suddenly or intensifies without obvious explanation, a GP should be asked to rule out a physical cause.

Is sundowning more common in care homes? Yes. Dementia UK estimates that around 80% of people with dementia in residential settings experience sundowning, compared with approximately 20% in community settings. This may partly reflect the additional environmental disruption involved in moving into care, as well as reduced staffing levels in the early evening.

Can sundowning be cured? There is no cure for sundowning, as it is closely linked to the underlying neurological changes of dementia. However, with consistent environmental adjustments, a structured daily routine and compassionate support, many families find that episodes become less frequent and less distressing over time.

Are there medications that help with sundowning? In most cases, medication is not the first approach. Where it is considered, it tends to target co-existing conditions such as depression, anxiety or insomnia rather than sundowning directly. Some sleep medications carry significant risks for people with dementia, including an increased risk of falls and fractures. Any decision about medication should be made in close discussion with a GP or specialist.

When should I seek medical advice? If the person with dementia is at risk of falling or leaving the home unsafely, if they are in significant distress, or if sundowning appears suddenly after a period of stability, seek medical advice promptly. Sudden changes in behaviour should always be assessed to rule out an underlying physical cause such as infection or pain.

Further reading

• Understanding Dementia: Symptoms and Diagnosis
• 7 Stages of Dementia: A Timeline for Carers
• Caring for Someone with Dementia: A Practical Guide

Sources

1. Reimus, M. and Sieminski, M. (2025). ‘Sundowning Syndrome in Dementia: Mechanisms, Diagnosis, and Treatment’. Journal of Clinical Medicine, 14(4), 1158. https://doi.org/10.3390/jcm14041158
2. Dementia UK (2023). What is sundowning in a person with dementia? Available at: https://www.dementiauk.org/information-and-support/health-advice/sundowning/ (Review date: July 2026)
3. Alzheimer’s Society (2024). Sundowning and dementia. Available at: https://www.alzheimers.org.uk/about-dementia/stages-and-symptoms/dementia-symptoms/sundowning
4. Alzheimer’s Association (2025). Sleep Issues and Sundowning. Available at: https://www.alz.org/help-support/caregiving/stages-behaviors/sleep-issues-sundowning
5. Richardson, K. et al. (2020). ‘Adverse effects of Z-drugs for sleep disturbance in people living with dementia: a population-based cohort study’. BMC Medicine, 18, 351. https://doi.org/10.1186/s12916-020-01797-w