Sundowning: Why It Happens, and How to Manage It

Families caring for someone with dementia often describe the same pattern: the afternoon is fine, dinner goes OK, and then — around dusk — something shifts. The person becomes restless, confused, sometimes agitated, sometimes anxious, sometimes inconsolable. By late evening or bedtime, they are calm again. The next afternoon, the cycle repeats.

This pattern has a name: sundowning, or "late-day confusion." It affects roughly one in five people with Alzheimer's disease and other dementias. It is exhausting for caregivers and distressing for the person experiencing it. There is no single cure, but there are specific, practical things that help.

What sundowning is

Sundowning is not a separate disease. It is a pattern of worsening cognitive and behavioral symptoms that occurs in the late afternoon, early evening, or night in people with dementia. Symptoms can include:

• Restlessness, pacing, wandering
• Confusion about time, place, or people
• Anxiety or fear without obvious cause
• Irritability or anger
• Hallucinations or paranoid thoughts
• Difficulty settling into sleep
• Rapid mood changes

Severity varies widely. Some families describe brief afternoon fussiness; others describe hours of agitation each evening. The pattern tends to worsen as dementia progresses and can be one of the stressors that tips families toward considering memory care.

Why it happens

No single cause has been pinned down, which is why the management is a set of strategies rather than a medication. The leading hypotheses, which probably all contribute:

1. Disruption of the body's internal clock

The circadian rhythm — the 24-hour biological clock that regulates sleep, hormones, body temperature, and alertness — is regulated in part by the suprachiasmatic nucleus in the hypothalamus. In Alzheimer's disease, this region is affected relatively early, which weakens the signals that tell the brain "it is evening, wind down." Without those signals, the transition from day to night becomes disorienting.

2. Fading light and shifting shadows

Low light in the late afternoon increases visual ambiguity. Shadows change shape; familiar rooms look unfamiliar; faces become harder to recognize. For a brain already struggling with visuospatial processing, dusk is when reality becomes harder to parse.

3. End-of-day fatigue and cognitive reserve

Cognitive effort accumulates through the day. By late afternoon, the person with dementia is operating with less reserve than they had at breakfast. Normal processing that was manageable in the morning now exceeds capacity.

4. Hunger, thirst, pain, or unmet needs

Any discomfort can trigger a sundowning episode. Urinary tract infections — common and notoriously under-recognized in older adults — are a well-known trigger. So are constipation, dehydration, pain from undiagnosed conditions, and medication side effects.

5. Environmental and social cues

The end of the day is often busier in a home: people returning from work, dinner being prepared, TV on, phone calls. The sensory load at the time the person is most vulnerable is often at its peak.

Triggers worth tracking

If sundowning is happening regularly, a short behavior diary over one to two weeks usually reveals patterns. Note, for each episode:

• Time of onset
• What happened just before (transitions, meals, visitors)
• What the person had to eat, drink, and sleep that day
• Medications taken in the afternoon
• Caffeine or alcohol exposure
• Pain signals (grimacing, guarding, changed posture)
• Signs of illness (fever, cough, changes in urine)

Patterns usually emerge within a week. A single change — moving a medication time, adding an afternoon snack — often reduces episodes meaningfully.

Practical management strategies

These are the interventions that have the strongest real-world track record. No single one solves sundowning; the combination of several usually helps.

Environment

• Maximize daylight exposure in the morning and midday. Bright light during the day helps reset the circadian rhythm. A morning walk, if possible, is better than most medications for sleep.
• Keep afternoons and evenings well-lit. Turn lights on before the transition to dusk, not after. Shadowy rooms are a direct trigger.
• Reduce evening sensory overload. Lower TV volume, fewer visitors at peak vulnerability, quieter music, dimmer-not-brighter lamps.

Routine

• Consistent daily rhythm. Same wake time, same meal times, same bedtime, every day. The brain uses routine as scaffolding when internal cues are weakened.
• A predictable pre-evening activity. A walk, a task, a visit — something engaging and repeated. Structured activity in the 4-to-6pm window reduces the vacuum that sundowning fills.
• Earlier and lighter dinner. Heavy late dinners worsen sleep and increase evening restlessness.

Physical

• Limit daytime napping to short periods (under 30 minutes, before 2pm). Long or late naps consolidate the day-night inversion.
• Address caffeine and alcohol. Both should be kept to morning-only, in small amounts, or eliminated.
• Physical activity during the day. Even 20 minutes of walking helps sleep pressure build appropriately.
• Manage pain deliberately. Undiagnosed pain from arthritis, constipation, or dental issues is a common silent driver.

Interaction

• Simple, calm redirection during an episode. Arguing or correcting a person in a confused state almost always escalates things. Instead: validate the feeling, redirect attention.
• Reduce choices. At peak vulnerability, too many options overwhelm. "Would you like to sit in the kitchen or the living room?" is easier than "What would you like to do?"
• Physical reassurance. A hand on the arm, a familiar blanket, a familiar song. Sensory grounding often works when verbal reassurance doesn't.

When to call the doctor

Sundowning is usually chronic, but any sudden worsening warrants a medical call. Common treatable causes:

• Urinary tract infection. In older adults, UTIs often present as sudden confusion rather than the usual urinary symptoms.
• Pneumonia or other infection.
• Dehydration.
• New medication or dosage change.
• Pain from an undiagnosed source.
• Constipation.

Any of those can dramatically amplify sundowning within days. A call to the primary care physician or clinic is appropriate before escalating to an emergency department, unless the person is acutely unwell.

About medications

Sleep and antipsychotic medications are sometimes used for sundowning, but they are usually not first-line. Several have significant risks in older adults with dementia — including increased fall risk, cognitive worsening, and, in the case of some antipsychotics, increased mortality. Non-medication strategies almost always come first; medications are a clinician-managed option for severe, refractory cases.

If a medication is being considered, ask the prescribing clinician specifically about the expected benefit, the risks, how long the trial will last, and how you will know if it's working.

Caregiver care

Sundowning is exhausting. The evening hours that used to be relaxing become the hardest of the day. A few things that protect caregivers:

• A plan for relief. A second family member, a home health aide, or a respite program for a few hours a week is not a luxury; it is necessary.
• Don't take escalation personally. Confusion is the disease, not the relationship.
• Connect with a support group. The Alzheimer's Association helpline (1-800-272-3900) can connect you to local resources.

Related reading

• 10 Warning Signs of Alzheimer's Disease
• Stages of Dementia: A Family Guide
• What to Do After a Low Clock Drawing Test Score
• Sleep and Dementia Risk

References

• Canevelli M, Valletta M, Trebbastoni A, et al. Sundowning in dementia: clinical relevance, pathophysiological determinants, and therapeutic approaches. Frontiers in Medicine. 2016;3:73.
• Alzheimer's Association. Sleep Issues and Sundowning. alz.org.

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Disclosure: Dr. Shimada is the founder of Tokei Health. This article is informational and is not a substitute for individual medical advice from your own clinician.