Clues to Sudden Changes in Behavior in Someone With Dementia


What can it mean if your normally cooperative loved one suddenly becomes surly, or if someone who has always liked to walk refuses to budge? It can be tempting to blame these behaviors on dementia. But more often, a sudden change in attitude or physical function reflects something else going on that warrants checking.

Look for other behavioral clues

Is the person more withdrawn or agitated than normal? Engaged in any unusual behaviors (more unusual than what's "normal" now)? These could be signs of emotional distress triggered by a previous bad experience the last time the person was in similar circumstances.

Look for other physical clues

Does your loved one seem feverish? Is he or she walking with a limp or favoring one side? Experiencing a loss of appetite? These may be signs of an underlying physical problem that should be checked by a doctor.

Look for other cognitive clues

Is he or she saying strange, disjointed things? Unsure of surroundings or the year? Look for changes from what has been customary for that person. One possible cause: delirium, which can be life threatening and requires immediate medical attention.

Look for environmental cues

Is there a new home health aide? Did the behaviors start in connection with a particular activity (a bad experience bathing in too-cold water last week, for example, could make the person skittish when the bathwater is run this week). Is your loved one hospitalized or recovering from a surgery or illness? Delirium is also a common complication among older adults with dementia who have been hospitalized.

Learn the telltale signs of delirium, a possible life-threatening explanation for sudden behavioral changes.


over 1 year ago, said...

A very common cause for sudden drastic changes in behavior and/or cognition in someone with progressing dementia can be related to a urinary tract infection (UTI) . Getting a urine test to diagnose or rule that out is a good choice.


over 3 years ago, said...

Thank you Paula for another well written article to help us with our Loved Ones.


about 5 years ago, said...

THIS ARTICLE HAS HELP ME GRATELY. SOME SIGHNS I SEE ARE HAPPENING. THIS OPEN MY EYES REALLY.THANK YOU VERY MUCH. PLEASE I NEES ALL THE HELP FOR MY MOM PLEASE, I SHAR THIS WITH MY BROTHERS AND SISTERS, WE AL DISCUSS THEES THINGS ALL THE TIME, I ND A HUG