"What is normal memory loss?" is a question that is posed, in some form or another, uncountable times per day by an aging public that is beginning to worry about the looming specter of Alzheimer's disease. The question of what constitutes normal memory loss is also carried in the press quite frequently. The published answers range from reasonably constructive to dangerously misleading. Here is a helpful perspective.
Understanding Memory Issues
Most of the time, when a person past the age of 40 suggests that her memory is not as good as it used to be, she is actually saying one of two other things. I describe each briefly below:
First, for people whose perceived memory loss manifests as "difficulty recalling names" or the "inability to find the right word," then they are probably experiencing "slow" memory and not "broken" memory (which would indicate a medical problem).
If, for example, your tennis serve has gotten slower since you were 25 and you accept that fact without fearing some underlying medical problem, then rest assured that your memory can slow as well, even if you are completely healthy. The final proof for these people is that, once reminded of the name they could not recall, they are able to instantly confirm it. This establishes that the information was still stored in their memory (not lost)—they just hadn't been able to recall it as quickly as they would have liked.
Second, for people who complain of losing track of things and not following through on details, the problem is generally one of distraction and/or overload.
When you have a job, a spouse, children, bills to pay, elderly parents to care for, college tuition to be met, etc., there are many things to think about in a given day. Many more, on average, than you probably had to think about in your twenties. While you once had the luxury of concentrating on far fewer demands, you may now regularly lose track of a few details among the much greater administrative burden of your daily routine.
These are two common groups of people who are worried about memory loss but are most likely completely healthy. One group is correctly sensing a slowdown in their retrieval speed and the other group is incorrectly attributing lack of focus to a recall deficit. Real memory loss is present when, given adequate time and the opportunity to focus, one cannot store and retrieve information that they have focused on storing and retrieving.
So let's get back to the question with which we began: what is normal memory loss? Most of the time, the people asking that question don't really have memory loss; they have either slow recall or distractions that are preventing them from storing the information in the first place. When neither of those explanations applies and the person truly cannot store and retrieve important information, the memory loss is real and, importantly, this is never normal.
When the memory loss is real, there will be an underlying cause of the problem that an enlightened physician can diagnose and treat. If your physician says it is "just old age" and neither of the two explanations above (slow recall and lack of focus) seems to apply, you should seek a second opinion from another physician.