Sundowning in someone with dementia typically looks like a sharp shift in behavior during the late afternoon or evening — agitation, confusion, pacing, anxiety, sometimes aggression or hallucinations — that seems to come out of nowhere as the day winds down. A person who was relatively calm at lunch may, by 4 or 5 p.m., become restless, frightened, or convinced that a stranger is in the house. They might pace the hallway, pluck at their clothing, shadow their caregiver from room to room, or shout at family members for reasons they cannot articulate. This cluster of neuropsychiatric symptoms is known as sundown syndrome, and according to the Alzheimer’s Association, roughly 20 to 45 percent of people with Alzheimer’s disease will experience it at some point during their illness.
Sundowning is not a separate disease. It is a recognized pattern of worsening symptoms tied to the time of day, most common during the middle and later stages of dementia. The causes are rooted in brain changes — damage to the internal clock, disrupted melatonin production, shifting neurotransmitter levels at dusk — but they are also shaped by environment, unmet physical needs, and caregiver routines. This article breaks down the specific behaviors to watch for, what drives them neurologically, the environmental and physical triggers that make episodes worse, and what caregivers and clinicians can actually do to reduce the frequency and severity of sundowning.
Table of Contents
- What Does Sundowning Actually Look Like in Someone With Dementia?
- Why Sundowning Happens — The Neuroscience Behind the Clock Breaking Down
- Environmental and Physical Triggers That Make Sundowning Worse
- What Caregivers Can Do to Reduce Sundowning Episodes
- When Behavioral Approaches Are Not Enough — Medication Risks and Realities
- How Sundowning Changes Across the Stages of Dementia
- What Research Suggests About the Future of Sundowning Treatment
- Conclusion
- Frequently Asked Questions
What Does Sundowning Actually Look Like in Someone With Dementia?
The symptoms of sundowning are varied and can look different from one person to the next, which is part of what makes it so disorienting for families. The Alzheimer’s Society UK describes a range of behaviors: agitation and restlessness such as pacing or fidgeting, confusion about where they are or what time it is, intense anxiety that may include crying or calling out repeatedly, and irritability that can escalate to shouting or physical combativeness. Some people experience hallucinations — seeing figures in the shadows or hearing voices — or develop paranoid beliefs, such as insisting a caregiver is stealing from them. Others engage in what clinicians call “shadowing,” following a family member so closely that the caregiver cannot leave the room without triggering distress. Sleep disturbance is another hallmark. WebMD notes that people experiencing sundowning often have difficulty falling asleep, wake repeatedly through the night, or develop a reversed sleep-wake cycle where they are up all night and drowsy during the day.
Consider a practical example: a woman with moderate Alzheimer’s who naps comfortably after lunch but by 5 p.m. begins insisting she needs to “go home” — even though she is home — paces to the front door repeatedly, becomes tearful when redirected, and then cannot settle into sleep until well past midnight. That sequence of escalating confusion, emotional distress, and sleep disruption is a textbook sundowning episode. It is worth noting that the prevalence estimates vary widely. A February 2025 peer-reviewed review published in the Journal of Clinical Medicine found that reported rates of sundowning range from as low as 1.6 percent to as high as 66 percent, depending on how symptoms are measured and which populations are studied. This spread reflects the fact that there is no single diagnostic test for sundowning — it is identified through behavioral observation, and milder cases may go unrecognized or be attributed to general dementia progression.
Why Sundowning Happens — The Neuroscience Behind the Clock Breaking Down
The most significant driver of sundowning is damage to the brain’s circadian rhythm system. The suprachiasmatic nucleus, a small region in the hypothalamus that functions as the body’s master clock, degenerates as dementia progresses. According to a 2025 NIH-published review, this neurodegeneration disrupts the sleep-wake cycle at a fundamental level, making it harder for the brain to distinguish between daytime alertness and nighttime rest. The result is a biological confusion that maps directly onto the behavioral confusion caregivers observe each evening. Neurochemistry plays a compounding role. People with Alzheimer’s disease produce less melatonin than healthy adults, according to research published in PMC.
Under normal circumstances, the brain shifts from dopamine-dominant daytime signaling toward melatonin production as dusk approaches — a smooth biochemical transition that promotes calm and sleepiness. UCLA Health researchers have noted that in dementia, this transition is dysregulated. Dopamine levels drop without a corresponding rise in melatonin, leaving the person in a neurochemical no-man’s-land that can manifest as agitation, fear, or disorientation. However, not every evening episode is sundowning, and this distinction matters. If a person with dementia becomes agitated only after a specific trigger — a loud television, a particular visitor, being rushed through dinner — that may be a situational response rather than a circadian pattern. True sundowning tends to recur with some regularity in the late afternoon or evening regardless of what else is happening. Misidentifying the cause can lead caregivers to pursue the wrong interventions, so tracking the timing and context of episodes over several days is an important first step before assuming sundowning is the explanation.
Environmental and Physical Triggers That Make Sundowning Worse
Even when the underlying cause is neurological, environmental factors can amplify sundowning dramatically. The Mayo Clinic identifies low lighting as a major trigger — as daylight fades, shadows increase and visual contrast decreases, which can cause a person with dementia to misinterpret what they see. A coat rack becomes an intruder. A dark hallway becomes threatening. Unfamiliar settings compound the problem; a person recently moved to a care facility or even visiting a relative’s home may sundown more intensely than they would in their own living room, because nothing around them provides the visual anchors their damaged memory depends on. physical needs are just as powerful.
The Alzheimer’s Association lists pain, hunger, constipation, urinary tract infections, fatigue, and depression as conditions that can amplify sundowning behaviors. A person who cannot articulate that their back hurts or that they need to use the bathroom may express that discomfort as agitation or aggression instead. One common scenario: a person with moderate dementia develops a urinary tract infection — which they cannot report — and their sundowning episodes spike in frequency and intensity for a week before anyone identifies the underlying infection. Once treated with antibiotics, the sundowning returns to its baseline level. Disrupted routines also play a role. A day with an unusual schedule — a medical appointment, a missed meal, visitors at an unexpected hour — can destabilize the already-fragile sense of order that a person with dementia relies on. Caregivers who maintain consistent daily patterns often report fewer and less severe sundowning episodes, which aligns with clinical guidance from both the Mayo Clinic and Dementia UK emphasizing the importance of structured routines.
What Caregivers Can Do to Reduce Sundowning Episodes
The first-line approach to managing sundowning is behavioral and environmental, not pharmacological. The Mayo Clinic recommends establishing structured daily routines, ensuring adequate daytime light exposure, reducing stimulation in the evening hours, and limiting caffeine and sugar intake later in the day. These are not dramatic interventions, but they address the root triggers directly. For example, keeping curtains open during the day and turning on bright, warm lights before dusk can ease the visual transition that often precipitates confusion. Playing familiar, calm music in the late afternoon can provide an auditory anchor that reduces anxiety. Light therapy has shown particular promise. The 2025 Journal of Clinical Medicine review noted that bright light exposure during the day — either through natural sunlight or a therapeutic light box — can help recalibrate disrupted circadian rhythms.
Music therapy, aromatherapy, and multisensory stimulation have also demonstrated effectiveness in reducing agitation, according to the same review. These non-pharmacological approaches have an important advantage: they carry no side effects. The tradeoff is that they require consistent effort and time from caregivers, which the review explicitly acknowledged — behavioral interventions are more efficacious than medication, but they demand intense caregiver involvement that is not always sustainable, particularly for family members managing care alone. Melatonin supplements represent a middle ground between behavioral strategies and prescription medication. The Cleveland Clinic notes that melatonin may help regulate the disrupted sleep-wake cycle in people with dementia. It is available over the counter, is generally well tolerated, and addresses one of the direct neurochemical deficits associated with sundowning. However, melatonin is not a cure-all, and its effects tend to be modest — it may improve sleep onset without significantly reducing the agitation or hallucinations that occur earlier in the evening.
When Behavioral Approaches Are Not Enough — Medication Risks and Realities
For some people, non-pharmacological strategies reduce but do not eliminate sundowning, and the severity of symptoms — particularly aggression or hallucinations — may create safety concerns that push families and clinicians toward medication. The 2025 NIH review classifies pharmacological options as second-line treatments, and for good reason. Sedatives and antipsychotics can be effective at controlling acute agitation, but they carry severe side effects in older adults with dementia, including increased risk of falls, stroke, and mortality. The FDA has issued black box warnings on antipsychotic use in elderly dementia patients, and these medications should be prescribed at the lowest effective dose for the shortest possible duration.
The limitation that families need to understand is this: there is no medication specifically designed to treat sundowning. The drugs used — antipsychotics like quetiapine or risperidone, benzodiazepines, or trazodone for sleep — are borrowed from other psychiatric contexts and applied to sundowning based on symptom overlap, not on targeted research. Their effectiveness varies considerably from person to person, and what helps one individual may sedate another into a fog without actually resolving the underlying agitation. Caregivers should insist on regular medication reviews with the prescribing physician and should not accept “just keep giving it” as a long-term plan. If a medication is not producing clear benefit within a few weeks, it should be reassessed rather than continued indefinitely.
How Sundowning Changes Across the Stages of Dementia
Sundowning is most common during the middle and later stages of dementia, according to the Mayo Clinic, but it does not always follow a predictable trajectory. In the middle stages, sundowning may begin as mild restlessness or increased confusion in the evening — noticeable but manageable. A person might repeatedly ask what time it is, become clingy with their spouse after dinner, or resist going to bed.
As dementia progresses into later stages, the same person may develop full episodes of shouting, attempting to leave the house, or experiencing vivid hallucinations that are genuinely terrifying to them. Not everyone with dementia will experience sundowning, and some who do find that it diminishes in the very late stages as overall activity and awareness decrease. Families should avoid assuming that the current pattern will remain fixed — tracking symptoms over weeks and months helps clinicians adjust care plans as the condition evolves.
What Research Suggests About the Future of Sundowning Treatment
The 2025 review in the Journal of Clinical Medicine represents a growing recognition in the research community that sundowning deserves more targeted study. For decades, it was treated as an inevitable feature of dementia rather than a distinct clinical challenge with its own mechanisms and potential interventions. The current evidence base, while improving, still relies heavily on small studies and observational data.
Larger clinical trials examining light therapy protocols, melatonin dosing, and combination approaches — behavioral strategies paired with low-dose pharmacotherapy — are needed to move the field from general recommendations to precise, evidence-based treatment guidelines. One promising direction involves chronotherapy — timing interventions to align with the individual’s disrupted circadian cycle rather than applying a one-size-fits-all schedule. As wearable technology improves and becomes more accessible, continuous monitoring of sleep patterns, activity levels, and even light exposure could allow caregivers and clinicians to personalize sundowning management in ways that are not currently practical. The goal is not to eliminate sundowning entirely — that may not be possible given the underlying neurodegeneration — but to reduce its frequency, blunt its severity, and give both patients and caregivers more peaceful evenings.
Conclusion
Sundowning in dementia is a convergence of broken biology and environmental pressure. Damage to the brain’s internal clock, depleted melatonin, dysregulated dopamine, and heightened sensitivity to shadows, noise, and unmet physical needs all collide in the late afternoon and evening, producing a recognizable pattern of agitation, confusion, anxiety, and sleep disruption that affects up to 45 percent of people with Alzheimer’s disease. Recognizing what sundowning looks like — and understanding that it is not willful behavior but a neurological symptom — is the first step toward managing it effectively.
The most effective responses are also the most labor-intensive: consistent routines, adequate lighting, daytime activity, calm evenings, and vigilant attention to pain, infection, and other physical triggers that amplify symptoms. Melatonin and light therapy offer additional support with minimal risk. Medication remains a last resort, effective in some cases but carrying serious side effects that demand careful oversight. For caregivers, the practical takeaway is to track patterns, address physical needs first, modify the environment before reaching for a prescription, and work closely with a clinician who understands that sundowning is not just “what happens with dementia” but a specific problem with specific — if imperfect — solutions.
Frequently Asked Questions
What time of day does sundowning usually start?
Sundowning typically begins in the late afternoon or early evening, often between 4 and 7 p.m., though the exact timing varies by individual. It can persist into the night and disrupt sleep well past midnight. The pattern tends to correlate with fading daylight, which is why it is more pronounced in winter months when dusk comes earlier.
Does sundowning happen every day?
Not necessarily. Some people experience sundowning most evenings, while others have episodes only a few times a week or during periods of illness, pain, or routine disruption. Tracking episodes in a journal for two to three weeks can help identify patterns and triggers specific to the individual.
Can sundowning happen in early-stage dementia?
It is possible but uncommon. The Mayo Clinic notes that sundowning is most common during the middle and later stages of dementia. If someone in the early stages shows significant evening agitation, it is worth investigating other causes — such as medication side effects, depression, or a urinary tract infection — before attributing it to sundowning.
Is sundowning the same as delirium?
No. Delirium is an acute change in mental status that can happen at any time of day, often triggered by infection, medication, or metabolic imbalance. Sundowning follows a time-of-day pattern and occurs in the context of an existing dementia diagnosis. However, delirium can worsen sundowning, and the two can overlap, so sudden changes in behavior should always be evaluated by a physician.
Does melatonin actually help with sundowning?
Melatonin may help improve sleep onset and regulate the disrupted sleep-wake cycle, according to the Cleveland Clinic, but its effects on the agitation and confusion components of sundowning tend to be modest. It is generally safe and worth trying as part of a broader management plan, but it is unlikely to resolve sundowning on its own.
Should I use a nightlight or keep the house dark at night?
Nightlights are generally recommended. Complete darkness can increase disorientation and fear in someone with dementia, while a soft, warm nightlight in hallways and bathrooms reduces the risk of falls and provides visual reassurance. Avoid bright or blue-toned light at night, which can further disrupt melatonin production and worsen sleep difficulties.
