Sundown Syndrome: The Basics

Sundown Syndrome The Basics

If you are acting as the caregiver for an elderly loved one, you may have run into sundown syndrome. Developing a working understanding of sundown syndrome will prove to be a valuable tool in providing the right level of care for your loved one.

What is sundown syndrome?

Simply put, sundown syndrome is a condition which often—but not necessarily always—affects elderly people who are already suffering from some form of dementia or cognitive issues. It is usually—but again, not always—most readily apparent around the time of the day when the sun sets.

People with sundown syndrome will begin to exhibit signs of agitation, restlessness, confusion, and even delirium. The signs may be mild, moderate, or severe, and may change in intensity from person to person. Further, the signs may vary in intensity in the same person from day to day, depending on the severity of the triggers the sufferer is experiencing as well as other factors such as diet, activity level, and outside environmental factors.

Sometimes those suffering from sundown syndrome will be relatively benign in their display of symptoms; other times they may yell, throw things, and lash out at those around them. While a caregiver should never scold or berate someone who is suffering from sundown syndrome—as that person will be unable to understand him or her and really is not responsible for his or her actions—you may need to take steps to protect everyone’s safety—that of the afflicted person as well as those around him or her.

What causes sundown syndrome?

There is no single isolated cause of sundown syndrome; rather, the syndrome seems to rise from any of several factors, or a combination thereof. For an elderly person in a long-term care facility, the increased activity of the staff and other residents as the day winds down and the staff goes through a shift change may contribute to anxiety, aggression, or confusion.

Another possible factor is fatigue. A person suffering from sundown syndrome may be tired at the end of his or her day, and—as we all can attest—people who are tired tend to be more irritable than they otherwise might be.


There is no single isolated cause of sundown syndrome; rather, the syndrome seems to rise from any of several factors, or a combination thereof.


A change in the light that comes as the sun sets may also contribute to the issue. While this is not as problematic in a building where the lights are kept on continually and everything is well-lit, as the sun sets and shadows start to deepen, this can frighten and frustrate elderly people who may already have a difficult time seeing very well.

Other researchers believe a shift in the internal biological clock may be responsible for at least some cases of sundown syndrome. Everyone has an internal clock that regulates how their body maintains itself during the day. With most people, the internal clock is set to a (roughly) 24-hour cycle, which coincides with their normal waking and sleeping patterns.

However, some research has suggested that people who suffer from dementia may also experience a shifting of this clock, leading the body to believe it should be sleeping when it is still early in the day. This in turn can lead to increased agitation, confusion, and so on in those who are already suffering from some form of cognitive impairment.


Sundown syndrome is a condition which may affect as many as one-fifth of elderly dementia patients; it is a condition that has numerous causes and is displayed in a variety of ways. While there is no one cure for the syndrome, it is important to understand the potential causes and triggers. A solid understanding of what your elderly loved one is experiencing and why this may be will assist you in developing routines to minimize the trauma brought about by sundown syndrome.

Sources (website). Sundowners Syndrome: Triggers & Management. May 7, 2015. Available at Last visited November 20, 2015.

Udesky, Laurie. Sundown Syndrome. Available at Last visited November 20, 2015.