Behavioral changes in the late afternoon and evening—commonly called sundowning or sundowning syndrome—can be one of the most distressing aspects of caring for someone with dementia. Yet, despite how frequently the term is used, there are persistent misconceptions about what it is, why it happens, and how best to respond. Better understanding can make a meaningful difference for both patients and caregivers, says Matthew Mulroy, MD, a UCLA Health internist who specializes in geriatric medicine.
What Is Sundowning?
People living with dementia may experience a range of behavioral and psychological symptoms, including irritability, agitation, aggression, disorientation, hallucinations, and paranoia, Dr. Mulroy explains. These symptoms often intensify later in the day—hence the term sundowning—but they are not limited to evening hours and can occur at any time.
One of the most important points for families to understand is that sundowning is common but not inevitable. “Many people with dementia never experience this issue,” Dr. Mulroy notes,
What Causes Sundowning Syndrome?
A common misconception is that sundowning is simply the result of being tired. While fatigue can play a role, Dr. Mulroy says the reality is more complex. Changes in the brain’s circadian rhythm—the internal clock that regulates sleep and wake cycles—are a major contributor. In addition, the late afternoon often brings reduced stimulation, fewer structured activities, and lower light levels, all of which can increase confusion and restlessness.
Sundowning: Dementia or Delirium?
Sundowning is most closely associated with Alzheimer’s disease and other forms of dementia, but similar symptoms can appear in another condition: delirium. Dr. Mulroy explains that when someone becomes suddenly confused, agitated, or disoriented due to an infection, medication effect, or other acute medical problem, the cause may be delirium rather than dementia. Unlike dementia, delirium is temporary and often reversible once the underlying illness is treated. Recognizing this distinction is critical, because delirium requires prompt medical evaluation.
Symptoms of Sundowning
Some changes linked to sundowning tend to appear in the late afternoon or evening, while others are symptoms that can occur at any point in the course of dementia. Common behaviors include repetitive movements such as pacing or rocking, wandering, shouting, crying, and difficulty sleeping. A person may also stay very close to a caregiver and follow them from room to room, or in some cases become physically or verbally aggressive.
These experiences are often accompanied by strong emotions. Individuals may seem unusually anxious, fearful, irritable, or restless, and some show signs of sadness or heightened agitation as the day goes on. Changes in thinking and perception are also common. People may become more disoriented, suspicious, or confused, and some develop false beliefs or see and hear things that are not there.
How Is Sundowning Diagnosed?
Sundowning is not a formal medical diagnosis, but rather a descriptive term used when a person with dementia shows a consistent pattern of increased confusion, agitation, or behavioral changes in the late afternoon or evening. Clinicians identify it by carefully reviewing the timing, frequency, and nature of symptoms, often relying on caregiver observations or a daily log to confirm that the changes reliably occur later in the day.
Because similar behaviors can be caused by treatable conditions, the evaluation also includes ruling out other medical or psychiatric issues, such as infections, pain, medication side effects, dehydration, sleep disorders, depression, or delirium. Providers consider the individual’s type and stage of dementia, since sundowning is more common in the middle to later phases, and they assess environmental and routine factors like lighting, activity level, napping, and overstimulation that may contribute to late-day distress. In this way, sundowning is recognized through a pattern of symptoms and the exclusion of other causes rather than through a specific test.
Treatment Options
Medication is often assumed to be the primary solution, but Dr. Mulroy cautions that this approach is frequently overused. Commonly prescribed medications may include antidepressants, anxiolytics (anti-anxiety drugs), antipsychotics, and melatonin.
Although drugs can sometimes help, environmental and behavioral strategies are typically more effective and carry far fewer risks for older adults, who are more vulnerable to side effects such as falls, sedation, and worsening confusion. These strategies include:
- Structure and consistency. For caregivers, the most effective interventions are often practical and nonpharmacologic. Dr. Mulroy recommends maintaining a structured and consistent daily routine, as predictability helps people with dementia feel more secure and oriented. The late afternoon and early evening—when symptoms are most likely to emerge—benefit from gentle structure. Light household tasks, listening to music, looking through photographs, sharing a snack, staying hydrated, or taking a short walk can provide calming engagement.
- Regular physical activity—adapted to the person’s abilities—can reduce restlessness and promote better nighttime sleep. Spending time outside during the day can also be helpful.
- Sleep management. Sleep is a cornerstone of prevention and management. Keeping consistent sleep and wake times, avoiding long daytime naps (especially those over 30 minutes), and ensuring regular mealtimes all support a stable circadian rhythm. Exposure to natural light, whether by spending time outdoors or sitting in a bright room, is another powerful tool.
- Respond calmly. When anxiety or agitation does occur, Dr. Mulroy advises a calm and reassuring approach. Arguing, correcting, or trying to force someone to “see reality” often escalates distress. Instead, caregivers should offer reassurance that the person is safe and gently orient them to the time, place, and situation.
- Allow the person to walk or pace if they feel the need.
- Ask whether something is bothering them when they seem upset, and gently orient them to the time of day.
- Discuss with the doctor which times are most appropriate for medications.
- Keep the home brightly lit during the evening to help minimize confusion.
- Limit or avoid alcohol, caffeine, and nicotine; they can interfere with sleep.
- Pay attention to what happens before late-day agitation, and note any possible triggers.
- Provide a more substantial meal at midday, and serve a lighter dinner.
- Reassure the person calmly that they are safe and that things are OK.
Source: Alzheimer’s Association
When Should You Seek Medical Advice?
You should seek medical advice if symptoms that resemble sundowning appear suddenly, become significantly more severe, or differ from the person’s usual pattern. A rapid change in behavior—such as increased confusion, agitation, sleepiness, or hallucinations developing over hours or a few days—can signal delirium, infection, medication reactions, dehydration, or pain, all of which require prompt evaluation.
Medical guidance is also important if the person becomes physically aggressive, wanders and cannot be kept safe, stops eating or drinking, has repeated falls, or is unable to sleep for several nights in a row. In addition, contact a health-care provider if the behaviors are causing extreme distress for the person with dementia or are becoming too difficult for the caregiver to manage at home.
Recovery and Outlook
Ultimately, understanding sundowning as a multifactorial and manageable phenomenon—not an unavoidable decline—can shift how families respond. With thoughtful routines, supportive environments, and a focus on reassurance rather than correction, evenings can become less stressful for everyone involved.
