Most people who notice their memory slipping may actually go on to develop Alzheimer's, say a study.
Self-reported memory complaints are strong predictors of clinical memory impairment later in life, the findings showed.
Alzheimer's is the most common type of dementia.
"What's notable about our study is the time it took for the transition from self-reported memory complaint to dementia or clinical impairment - about 12 years for dementia and nine years for clinical impairment - after the memory complaints began," said Richard Kryscio from University of Kentucky in the US.
"That suggests that there may be a significant window of opportunity for intervention before a diagnosable problem shows up," Kryscio added.
For the study, the researchers asked 531 people with an average age of 73 years and free of dementia whether they had noticed any changes in their memory in the prior year.
During the study, 56 percent of the participants reported changes in their memory, at an average age of 82.
The study found that participants who reported changes in their memory were nearly three times more likely to develop memory and thinking problems.
About one in six participants developed dementia during the study, and 80 percent of those first reported memory changes.
The study appeared in the journal Neurology.
