The term "sundowning" refers to a state of confusion occurring in the late afternoon and spanning into the night. Sundowning can cause a variety of behaviors, such as confusion, anxiety, aggression or ignoring directions. Sundowning can also lead to pacing or wandering.

Sundowning isn't a disease, but a group of symptoms that occur at a specific time of the day that may affect people with dementia, such as Alzheimer's disease. The exact cause of this behavior is unknown.

Factors that may aggravate late-day confusion include:

• Fatigue
• Low lighting
• Increased shadows
• Disruption of the body's "internal clock"
• Difficulty separating reality from dreams
• Presence of an infection such as urinary tract infection

Tips for reducing sundowning:

• Try to maintain a predictable routine for bedtime, waking, meals and activities.
• Plan for activities and exposure to light during the day to encourage nighttime sleepiness.
• Limit daytime napping.
• Limit caffeine and sugar to morning hours.
• Keep a night light on to reduce agitation that occurs when surroundings are dark or unfamiliar.
• In the evening, try to reduce background noise and stimulating activities, including TV viewing, which can sometimes be upsetting.
• In a strange or unfamiliar setting, bring familiar items — such as photographs — to create a more relaxed, familiar setting.
• Play familiar gentle music in the evening or relaxing sounds of nature, such as the sound of waves.
• Talk with your loved one's doctor if you suspect that an underlying condition, such as a urinary tract infection or sleep apnea, might be worsening sundowning behavior, especially if sundowning develops quickly.

Some research suggests that a low dose of melatonin — a naturally occurring hormone that induces sleepiness — alone or in combination with exposure to bright light during the day may help ease sundowning.

When sundowning occurs in a care facility, it may be related to the flurry of activity during staff shift changes or the lack of structured activities in the late afternoon and evening. Staff arriving and leaving may cue some people with Alzheimer's to want to go home or to check on their children — or other behaviors that were appropriate in the late afternoon in their past. It may help to occupy their time with another activity during that period.