Eyes and ears
Vision tends to worsen over time. Octogenarians often need reading glasses and become more sensitive to glare, Dr. Morrison said. Nearly 70 percent of adults over 80 have cataracts, a clouding of the lens of the eye, but the condition can be treated effectively with surgery, he said.
Age-related hearing loss is another common problem. First, people lose the ability to hear high-frequency sounds such as bird chirps and alarm clocks; this can start early, even in a person’s 30s or 40s. Low-frequency changes, affecting the ability to hear men’s voices and bass sounds in music, come later. Hearing loss can be treated with hearing aids — now available over the counter — or other devices, and it’s crucial to do so: “We have increasing data now that suggests that people who go longer with untreated hearing loss and don’t get hearing correction are more likely to develop dementia or diseases like Alzheimer’s disease,” Dr. Morrison said.
Heart and lungs
As a person ages, heart rate slows slightly, and the heart can’t beat as fast during physical activity, which can make aerobic exercise more challenging. That said, an aging healthy heart typically “functions quite well,” said Dr. Lona Mody, a geriatrician at Michigan Medicine.
Doctors monitor for heart disease in their octogenarian patients. “Blood vessels become stiffer with age, and this leads to higher blood pressure,” Dr. Mody said, which can increase the risk of hypertension and heart disease. According to the American Heart Association, 83 percent of men and 87 percent of women age 80 and older have heart disease, sometimes requiring the use of medications or surgery. Mr. Biden has asymptomatic atrial fibrillation — an irregular heartbeat — and takes apixaban (Eliquis), an anticoagulant drug that is often prescribed to help prevent blood clots and strokes. He also takes rosuvastatin (Crestor) to lower his cholesterol.
Lung capacity often slightly drops with age because of changes in the strength and elasticity of the lung tissue and diaphragm, which can make breathing a bit harder, Dr. Mody said. One disease doctors look out for is chronic obstructive pulmonary disease, an inflammatory lung disease seen in just under 11 percent of people 65 and over.
Digestive system
People in their 80s tend to eat less than they used to, in part because “food doesn’t taste quite the same,” Dr. Morrison said. Over time, people lose taste buds and their sense of smell, he said, both of which affect how much they enjoy eating. This helps to explain why older adults have an increased risk of nutritional deficiencies.
But seniors also need fewer calories than younger people because of losses in lean muscle mass and slowing metabolism. According to the government’s Dietary Guidelines for Americans, women age 60 and older should consume a minimum of 1,600 calories a day, and men age 60 and older a minimum of 2,000 calories a day (as opposed to a minimum of 1,800 for women and 2,400 for men ages 19 to 30).