Ever ask someone how their family member passed away and hear them say they simply "died of old age?"
As it turns out, that's almost never quite what's going on from a medical perspective. Aging—in and of itself—is not a cause of death, according to Business Insider.
When most of us say that someone died of old age, what we really mean is that someone died as a result of an illness (like pneumonia) or as a result of an event (like a heart attack) that a healthy, stronger, younger person would likely have survived.
The Centers for Disease Control and Prevention keeps track of what people actually die from in the United States. In 2020, the CDC said the number one cause of death for people over the age of 65 in the US was heart disease, followed by cancer, COVID-19, cerebrovascular disease (which often leads to strokes), and Alzheimer's.
These "old age" fatalities are often quiet deaths, like what happens when you hear an older person's heart stopped in their sleep. That usually means the person had a heart attack in the middle of the night. Another example is if someone "had a bad fall, and it was just downhill from there." The person likely broke a hip, survived the surgery, but then got pneumonia and died as a result of their infection.
Often, what claims the lives of older people can be an accumulation of things. Sometimes this is referred to as "geriatric failure to thrive," a kind of catchall phrase for elderly patients who may have a bunch of interrelated issues, including trouble with moving, eating, depression, and cognitive impairment.
Humans didn't always live reliably long enough to age. People used to die frequently long before their skin began to sag or their muscles began to wither, succumbing instead to diseases for which we now have vaccines, like tuberculosis or smallpox. Some people died from gastrointestinal infections, which can cause diarrhea. In many countries around the world, diarrhea is still a leading cause of death in kids, along with malaria, and pneumonia.
Somewhere around the 1950s (at least in the US, and other wealthy countries), we started living nearly twice as long as our ancestors had just a century before. We now spend a massive portion of our lives getting old before we die, though in recent years, life expectancy has been declining — a trend that started before the COVID-19 pandemic began.
What if we experienced aging without death as the final outcome—or didn't age at all? That's how some animals do it.
A 2014 study comparing the mortality rates of 46 different species found that some organisms don't age—their mortality rates stay constant from around the time they're born until around the time they die. Others enter a period of aging (like the kind most of us experience around age 65) and then come out of it, continuing their lives.
Some scientists think we can use this knowledge of the natural world to stop aging, or at least prolong human life.
For us, aging is real, and it is long. Fortunately, many older people can still live healthy, happy lives.