Sundowning (also called sundown syndrome) refers to incidences of increased restlessness, aggression, and disorientation among those with Alzheimer’s disease and other types of dementia. In sundowning, these symptoms are usually observed late in the afternoon, continuing throughout the evening.

While sundowning is a recognized phenomenon in people with Alzheimer’s, not all doctors agree on what symptoms define it clinically or what causes it. Experts believe sundowning might have something to do dementia’s effects on the circadian rhythm (the cycle of sleeping and waking).

Sundowning impacts the affected individual’s quality of life, as well as that of their families and caregivers. Certain lifestyle adjustments and medications can sometimes ease sundowning symptoms.

In this article, we’ll go over risk factors and symptoms of sundowning, and the ways it can be managed.

There’s currently no formal diagnostic criteria or tests used to diagnose sundowning. However, doctors will look for certain factors. This includes cognitive, behavioral, and emotional symptoms that are common among people experiencing sundowning.

To someone’s loved ones, sundowning may look like a noticeable change in their personality and behavior. Sundowning can also look like a worsening or flare of existing dementia symptoms.

Among the more recognizable signs and symptoms of sundowning are:

  • agitation
  • anxiety
  • confusion
  • disorientation
  • pacing, wandering off
  • aggression (including yelling, being resistant)

Some people with sundowning may also experience visual disturbances or hallucinations.

Sundowning is experienced most often by people with Alzheimer’s disease or other types of dementia, such as Lewy body dementia.

Not all people with dementia will experience it. The Alzheimer’s Association reports that as many as 20 percent of people with Alzheimer’s or dementia may experience sundowning.

Dementia is a category of multiple diseases — including Alzheimer’s — that affect cognitive functioning. It occurs when many neurons (healthy brain cells) stop functioning properly. Dementia can also affect someone’s regulation (control) of their emotions, leading to unpredictable behavior and outbursts.

According to the National Institutes of Health (NIH), main symptoms of dementia include, among others:

  • memory loss
  • poor judgement or decision making
  • confusion
  • getting lost or disoriented in familiar places
  • difficulty speaking and expressing yourself
  • difficulty performing daily functions (including paying bills, driving, getting dressed)

Exact symptoms vary depending on what type of dementia you or a loved one is experiencing. Alzheimer’s is the most common form of dementia by far. The World Health Organization (WHO) reports that Alzheimer’s contributes to 60 to 70 percent of all dementia cases.

Sundowning after anesthesia

Older adults who undergo anesthesia during major surgery may also experience symptoms similar to sundowning temporarily in the days following their procedure. This can be a result of post-operative delirium, a temporary phenomenon in which individuals wake up from anesthesia, disoriented and unable to focus or communicate clearly.

A 2020 study with people who had undergone hip fracture surgery reported that nearly 30 percent of participants experienced some form of post-operative delirium.

Researchers are still trying to understand why some people with dementia experience sundowning, and others don’t. It appears both biological and environmental factors play a role.

A main theory is that brain changes brought on by Alzheimer’s or other dementias may interfere with a person’s circadian rhythm. The circadian rhythm is like the body’s clock, regulating a person’s sleep-wake cycle, hormones, digestion, and other functions.

One 2020 study noted that sundowning seems to be more tied to emotional disruption, not just sleep disturbance. This can also be tied to the circadian rhythm, which has a huge impact on people’s moods.

The authors said further study of the circadian system may bring about improved understanding of, and treatment options for, sundowning.

The study also identified the following factors as potentially contributing to sundowning:

  • environmental overstimulation (too much noise, crowds, bright lights)
  • certain medications (including antipsychotics and antidepressants)
  • having a sleep disorder
  • having a mood disorder, including depression
  • chronic pain
  • inattentive caregivers causing boredom
  • too little light
  • hunger
  • body temperature changes

A 2016 study also pointed to the circadian rhythm as a key player in sundowning. Authors noted Alzheimer’s patients who exhibited sundowning had higher levels of the hormone cortisol, which can cause a state of high stress and trouble sleeping.

Melatonin is another hormone used in the circadian rhythm to regulate the sleep-wake cycle. Melatonin often decreases naturally with age, and some patients with Alzheimer’s have been found to have especially low rates.

Because sundowning happens at the end of the day, it can present a unique challenge to loved ones or caregivers who may be over-tired.

Read more about how to care for yourself if you have caregiver burnout.

If sundowning occurs every day, or if symptoms get more severe, the behaviors can signal a worsening of dementia. Sometimes, this means considering a change in living or caregiving arrangements for the affected person.

For example, if sundowning becomes too much for a spouse or other caregiver to handle, a move to a skilled nursing facility (nursing home) may be necessary.

If a person tends to wander off during sundowning episodes, there’s always the risk of injury. Being in a more secure, monitored environment could be beneficial for their safety.

Deciding to change your loved one’s living arrangements can be emotional and overwhelming, and it may be financially difficult. Reach out to family and friends for support, and stay in regular communication with your doctor about recommendations.

If possible, consider seeing a therapist to help cope and have a safe space to talk.

Because the origins of sundowning aren’t well known and may differ from one individual to the next, treating or managing the condition can be challenging. Keep in mind the risk factors for sundowning, and how multiple factors are likely working together to cause an episode of sundowning.

It may take some experimenting to find changes to a person’s schedule or lifestyle that make a difference.

The National Institute on Aging offers some potentially helpful strategies to cope with, and prevent, sundowning.

Helpful strategies

  • Make sure they get physical activity every day.
  • Reduce noise, crowding and clutter in their room.
  • Close blinds to minimize shadows, which can cause confusion. Turn on lights inside (but not too bright).
  • Distract them with a snack, activity, or favorite TV show to keep them occupied and content.
  • Try to make evening time quiet and calming. Incorporate music, reading a book, or a walk. Consider having a loved one call.
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Things to avoid

  • drinking caffeine late in the day
  • drinking alcohol
  • an overly busy schedule
  • too many naps late in the day
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Make sure the person experiencing sundowning experiences an appropriate amount of time in the sun whenever possible. A 2020 study with 46 Alzheimer’s patients in China suggested that morning or afternoon walks of 30 minutes can significantly reduce sundowning behaviors.

One other treatment that is generally safe and well tolerated is light therapy. Exposure to natural light in the morning can help maintain a person’s circadian rhythm.

If that isn’t always possible, a special box light specifically designed for light therapy — often helpful in treating depression — may be useful.

It’s important for them to have comfortable sleeping arrangements and plenty to eat and drink during the day. Other health conditions, including chronic pain, should be addressed.

If someone is experiencing sundowning and becoming agitated or aggressive, don’t escalate the situation by raising your voice or becoming physical. The NIH recommends calmly listening to the person’s concerns and providing reassurance. Distract them with their favorite activities or a different subject.

Medical treatment of sundowning may involve medications. This can include medications and supplements to treat or prevent sundowning’s symptoms, or to address another health condition that may be contributing to sundowning.


One possibility is the over-the-counter sleep supplement melatonin. Melatonin may help correct an individual’s sleep-wake cycle and allow them to fall and stay asleep.

The average starting dose is 3 milligrams (mg), but note that melatonin should be taken about an hour before bedtime, not right before the person tries to fall asleep.

Always talk with a doctor before beginning you or another person on any new supplements.

Check out our list of the year’s best melatonin supplements and gummies.

Other medications

Stronger prescription medications may be helpful in treating sundowning symptoms, or underlying conditions that impact it. However, it’s important to remember these medications are not currently approved by the Food and Drug Administration (FDA) to treat dementia behaviors.

These medications include:

  • antipsychotics
  • antidepressants
  • benzodiazepines

The side effects of certain medications may be too high risk for some older adults. There may also be interactions with medications the person is already taking.

Consult a doctor if you think your loved one might benefit from medication changes, and make sure the doctor is aware of all current medications your loved one is taking.

Overall, there’s limited research into the treatment of sundowning with medications.


Cannabinoids are compounds found in the Cannabis sativa plant that naturally contains around 540 chemicals. The most common cannabinoids used from the plant are tetrahydrocannabinol (THC) and cannabidiol (CBD).

Learn more about the difference between THC and CBD.

Cannabinoids have shown promise as an alternate dementia treatment method, although more trials are needed, and nothing is FDA approved yet. It’s believed that cannabinoids have the potential to interact with the neurotransmitters involved in dementia’s neuropsychiatric symptoms, such as memory loss, disorientation, and moods.

A 2019 research overview summarized that 4 out of the 12 studies the authors examined found medical cannabis treatment significantly improved “a range of neuropsychiatric symptoms associated with dementia.” The remaining 8 studies did not find any evidence to support its efficacy.

Sundowning is a set of behaviors in the late afternoon and evening primarily seen in people with dementia. The symptoms include increased agitation, confusion, and disorientation. Some people in a sundowning phase may become aggressive, yelling and resisting aid or instructions.

Research into the phenomenon of sundowning is ongoing, and the dementia’s relationship to the circadian system is one promising avenue.

Watching a loved one go through sundowning can be stressful, and even traumatizing. And for some caregivers, dealing with sundowning at the end of a long day may contribute to burnout.

However, with careful attention to environmental, health, and lifestyle factors, sundowning symptoms may become more manageable.

Talk with your loved one’s doctor if you witness new or worsening dementia symptoms, or if you’re having difficulty managing a home care routine.