What Constitutes Normal Aging?

"What does normal aging look like?

That question has been at the center of a fervid national conversation since last month's presidential debate, when 81-year-old Joe Biden's struggles against Donald Trump, 78, set off widespread speculation about the president's seeming decline.

Both men, who if elected would each be the oldest person ever sworn-in as U.S. president, have slipped up facts or botched remarks in public, fueling attacks about their fitness from both sides. Biden and Trump both maintain they are in robust health.

Watching an older adult display signs of aging is all too familiar within many families, as are questions about what a slowed gait or confused speech signals, and whether an aging person can still, say, drive a car or live independently. Sometimes, aging is a steady decline; other times, it can appear to happen more rapidly.

As older adults make up a growing share of the U.S. population, there is heightened interest in recognizing signs of healthy or abnormal age-related decline. The number of adults age 65 and older increased by 9.4% between 2020 and 2023, to nearly 60 million.

Aging carries an increased risk of developing conditions that can interfere with physical and mental health. Most older people have at least one chronic health condition, and many have multiple. Signs of aging can appear differently for everyone, gerontologists and geriatricians say, so it can be hard to determine what is normal.

"People vary. Some people decline a little bit more in these areas, a little quicker. Some people maintain it and never decline," says Dr. Mary Tinetti, a geriatrician and professor of medicine at the Yale School of Medicine.

The brain and memory

There's a distinction between the usual mental decline that accompanies aging and mild cognitive impairment, which can progress to dementia, says Dr. John Rowe, a professor of health policy and aging at Columbia University.

Mild cognitive impairment affects roughly 12% to 18% of people age 60 and older, according to the Alzheimer's Association.

Short-term memory deficits, such as misplacing keys or forgetting people's names more often, is generally nothing to worry about, aging specialists say. 

Memory lapses that affect daily life, like forgetting to pay the bills, missing appointments or getting lost in familiar places could signal something more serious.

Changes in cognitive function tend to happen over months or years, says Rowe. Sudden decline, over a period of weeks, could be caused by illness, medication interactions, or a brain injury.

Disorientation, lack of social engagement and apathy can be early signs of dementia, says Dr. David Reuben, who directs the University of California, Los Angeles Alzheimer's and Dementia Care Program and geriatrics division.

Doctors use assessments of recent and long-term memory, recall, visual and spatial deficits and executive functioning to diagnose cognitive impairment. Regular testing allows doctors to track trends over time, which is more powerful than looking at any one data point, geriatricians say.

"It's very tempting to judge people in terms of their physical frailty or cognitive capabilities based on glimpses," says Reuben. "But an evaluation takes more than that."

Doctors note it's not all downhill. Aging can come with benefits, such as improved problem-solving, empathy and vocabulary skills.

Physical strength

People tend to lose strength, endurance, flexibility and organ function as they age. Balance and gait are often affected by these changes, which can increase the risk of dangerous falls. Smoking, obesity and diabetes raise the risk of earlier onset of certain age-related problems.

Regular stumbles, trouble getting out of chairs, or stiff movement with limited arm swinging while walking could signal an underlying condition, such as arthritis or neurological conditions like Parkinson's, geriatricians say.

Frailty, an age-related syndrome characterized by symptoms such as weakness, poor balance and unintentional weight loss, affects between 5% and 17% of older adults. Those with frailty, which can be diagnosed with the help of specific assessment tools, are at higher risk of falls, disability and death.

On the other hand, physical changes like walking more slowly, diminished hearing and needing to urinate more frequently are generally signs of standard age-related decline and not cause for worry, doctors say.

"If you're not as good at pickleball as you were last year, that probably doesn't need an evaluation," says Reuben.

Good days and bad days

People at any age have days when they don't feel their best or sharpest. The variability of "good" and "bad" days is likely to be more pronounced among older people, geriatricians say.

The body and brain's resilience, or reserve, declines as people age, so a poor night of sleep, mild illness or medication change can hit harder. A college-aged student might not be thrown off much by an all-nighter of studying, for example.

"But if you're an older adult with a little bit less reserve and you've had a tough night, you're on a medication that you're not familiar with, or you've got a viral infection, you could have cognitive and physical issues as a result," says Dr. Richard Stefanacci, a geriatrician and adjunct assistant professor at Jefferson College of Population Health in Philadelphia." [1]

1. An Age-Old Question: What Constitutes Normal Aging? --- Short-term memory loss is often not a worry; getting lost in familiar places could be more serious. Janin, Alex.  Wall Street Journal, Eastern edition; New York, N.Y.. 11 July 2024: A.10.