Understanding Sundowning: An Important Elderly Concern

Health Professional, Medical Reviewer

What is Sundowning?

Sundowning refers to a state of confusion that typically starts at the end of the afternoon hours and extends into the evening.  This is most commonly seen in elderly people, who either live alone or in an assisted-living environment, who are reported as acting strangely or even behaving violently, usually in the late afternoon or early evening hours.  A family member who is responsible is alerted, and then the difficult decision of “what to do” has to be tackled. Quite often, family members live a distance away and are not prepared for this scenario.

Who is at risk for sundowning?

The condition usually occurs in elderly individuals with a range of early dementia to full blown Alzheimer’s disease.  Behaviors may differ based on the degree of brain deterioration. Patients with early dementia typically have shrinkage of the layers of brain cells and learn to live with the decreased memory capabilities.  Eventually, the simplicity of their lives makes the dementia less noticeable.

People with Alzheimer’s disease have full deterioration of all parts of the brain, including entangling of the nerve fibers, and in many cases, these individuals cannot hold a coherent conversation.  These varying levels of brain deterioration interact with the fading light of the day differently.


In sundowning, there is increased general confusion as the natural light of the day begins to fade, and agitation follows as people become frustrated with their own confusion.  Sundowning behavior is aggravated by the mental and physical fatigue that increases for the elderly at that time of the day, resulting in heightened irritability. The individual becomes more resistant and upset with caregivers.  This irritability in turn results in worsening of tremors that many of the elderly develop, and movements become more uncontrollable.

Why does sundowning happen specifically at this time of the day?

The theory is that there is a disruption in the circadian rhythm of individuals who exhibit this behavior. This is set off by the part of the brain known as the suprachiasmatic nucleus (SCN), which also becomes affected by the tangles associated with Alzheimer’s disease.   The situation is further aggravated by the fact that the elderly often spend too much time indoors -either at home or in institutions- so they’re not entrained by the change in natural light during the day’s cycle.   Natural light changes are one of the prominent environmental cues (Zeitgeber) that govern our body clock in the circadian cycle.

Sleep disorders and sundowningSome of my past blogs discuss sleep schedule disorders.  The elderly often suffer with** advanced sleep schedule**, where they go to sleep early and awaken in the middle of the night and are unable to fall back asleep.  Frequently this cycle causes wandering at odd hours of the night, a potential harmful behavior that can be part of sundowning.

The other sleep disorder pattern is irregular sleep schedule disorder, in which there is no clear structure to the day so there is a blurring of sleep and wake schedule. The result is disorientation due to inability to separate dreams from reality, which can be a very frightening experience.  Again, this can explain the sundowning behavior.

What to do if a loved one is suffering with sundowning?** The following are some recommendations to help the individual and caretakers:**

  • Try to maintain a regular and predictable daily schedule.
  • Encourage the person with dementia to have a regular routine of meals, and wake up and go to bed at the same time daily.
  • Daily sunlight exposure is important.  This may be a problem for those who are living alone, but for people who live in assisted-living environments, there should be exposure to sun and natural light during the day, as well as engaging, stimulating activities early in the day to reinforce the difference between day and night.
  • Do not allow the individual to go to bed too early, even if he is excessively tired.
  • Try to maintain a regular sleep time to avoid awakening in the middle of the night. Discourage afternoon napping.
  • Avoid large meals, caffeine, or stimulating activities at night.
  • Make sure TV programming is not too stimulating or upsetting.
  • Keep a night light on in the corner of the bedroom to reduce agitation when surroundings are unfamiliar during nighttime awakening.

Are there any medications or medical therapies to treat sundowning?

No medications have been approved by the FDA for the specific treatment of sundowning. Melatonin has been used to reset the circadian schedule.  Very commonly, sedatives such as Risperdal or Haldol have been used by doctors in institutional settings. This may solve the problem for the institution but it does not address the root cause of the sundowning behavior. Antidepressants, if used, are problematic because they may cause excessive sedation and flattening of the (emotional) affect of the individual. Finally, Tegretol, an anti-colvulsant agent has been used off label for this purpose.

It is crucial to identify sundowning behavior so that steps can be taken to help the individual and so that inappropriate, even harmful medications are not used.  This can require a team effort of caregivers, family members and the patient working together so that quality of life is restored.


Alzheimer’s Association

Alzheimer’s Association

Mayo Clinic

For more information also check out Sleep Disorders