Children born today in the United States can expect to live nearly 78 years. That life expectancy is a great leap forward from 1900, when the average newborn couldn’t expect to reach age 50. Similar increases have been seen in in developed nations all around the world. In the 20th century, life expectancy increased more than it had in any century since the beginning of human civilization.
And the longer you live, the longer you can expect to live. Average life expectancy for a newborn American is 78 years, while it is 84 years for a 65-year-old and 87 years for a 75-year old.
But extending the lifespan has also increased the burden of diseases such as heart disease, stroke, cancer, arthritis, osteoporosis, macular degeneration, and other conditions that tend to affect older individuals. Most of these diseases, though, aren't inevitable consequences of aging. Instead, many are preventable.
Solid research from long-term studies such as the Framingham Heart Study, the Nurses' Health Study, and others have shown that the combination of not smoking, eating a healthy diet, exercising regularly, and keeping blood pressure, cholesterol, and blood sugar in check can prevent three-quarters or more of these chronic conditions.
Bedsores, also called pressure ulcers or decubitus ulcers, are areas of broken skin that can develop in people who:
Have been confined to bed for extended periods of time
Are unable to move for short periods of time, especially if they are thin or have blood vessel disease or neurological diseases
Use a wheelchair or bedside chair (a hospital chair that allows a patient to sit upright next to the bed)
Bedsores are common in people in hospitals and nursing homes and in people being cared for at home. Bedsores form where the weight of the person's body presses the skin against the firm surface of the bed.
In people confined to bed, bedsores are most common over the hip, spine, lower back, tailbone, shoulder blades, elbows and heels. In people who use a wheelchair, bedsores tend to occur on the buttocks and bottoms of the feet.
This pressure temporarily cuts off the skin's blood supply. This injures skin cells. Unless the pressure is relieved and blood flows to the skin again, the skin soon begins to show signs of injury.
The pressure that causes bedsores does not have to be very intense. Normally, our skin is protected from being injured by pressure because we move frequently, even when asleep.
At first, there may be only a patch of redness. If this red patch is not protected from additional pressure, the redness can form blisters or open sores (ulcers). In severe cases, damage may extend through the skin and create a deep crater that exposes muscle or bone.
Muscle is even more prone to severe injury from pressure than skin. A bedsore can involve several layers of damaged tissue.
Although pressure on the skin is the main cause of bedsores, other factors often contribute to the problem. These include:
Shearing and friction — Shearing and friction causes skin to stretch and blood vessels to kink, which can impair blood circulation in the skin. In a person confined to bed, shearing and friction occurs each time a person slides across the bed sheets.
Moisture — Wetness from perspiration, urine or feces makes skin under pressure more likely to suffer injury. People who can't control their bladders or bowels (people who are incontinent) are at high risk of developing bedsores.
Decreased movement — Bedsores are common in people who can't lift themselves off the bed sheets or roll from side to side. Without these small movements throughout the day, skin that is pressing against the bed does not get a steady supply of oxygen and nutrients. Blood flow is inadequate in these parts of the skin. (People who can move without assistance have a lower risk of bedsores because they can shift their weight periodically.)
Decreased sensation — Bedsores are common in people who have nerve problems that decrease their ability to feel pain or discomfort. Without these feelings, the person cannot feel the effects of prolonged pressure on the skin.
Circulatory problems — People with atherosclerosis, circulatory problems from long-term diabetes or localized swelling (edema) may be more likely to develop bedsores. This is because the blood flow in their skin is weak, even before pressure is applied to the skin.
Poor nutrition —Bedsores are more likely to develop in people who don't get enough protein, vitamins and minerals.
Age — Elderly people, especially those over 85, are more likely to develop bedsores because skin usually becomes more fragile with age.
Bedsores can lead to severe medical complications, including bone and blood infections.
As you age, years of being in the sun start to add up. Age spots (also called liver spots or solar lentigo) are collections of pigment caused by exposure to the sun. Pigment is deposited as a response to injury, just like a scar is a response to a cut. The pigment collects in areas injured because of thin skin or greater sun exposure. Age spots also can be caused by bruising that leaves blood pigment behind. They are most common in people older than 55. The spots commonly appear on the hands, but they can be almost anywhere, especially sun-exposed areas, such as the face, back, arms, feet and shoulders.
The thought of aging conjures some common perceptions: wrinkles, gray hair, a slightly stooped posture, perhaps some "senior moments" of forgetfulness. In fact, the process of aging has a nearly universal impact on our bodies, affecting our cells, tissues, organs, and body systems. The effects of aging can be seen in everything from our vital signs (like blood pressure) to our skin, to our bone and joints, to our cardiovascular, digestive, and nervous systems, and beyond. Some aging changes begin early in life. For example, your metabolism starts to gradually decline beginning at about age 20. Changes in your hearing, on the other hand, do not usually begin until age 50 or later.
We do not yet fully understand the complex interplay of factors that cause us to age as we do. Most likely, the vast and varied changes associated with aging result from a lifetime of environmental and cultural influences, as well as genetics, diet, exercise, illness, and a host of other factors, all of which contribute to the aging process.
A series of remarkable biological research studies since the 1990's have identified genes that can profoundly influence the rate at which cells, and animals, age. The good news from these studies is that biological changes that extend life also seem to extend vitality: animals that live longer remain quite healthy for most of their lengthened life. None of these discoveries is close to providing a "fountain of youth" for humans, but some scientists believe that research breakthroughs regarding aging in the 21st Century will lead to the development of drugs that can extend human life and simultaneously improve human health.
Following are examples of how aging affects some of our major body systems.
Cells, organs and tissues:
Cells become less able to divide
The telomeres—the ends of the chromosomes inside every cell—gradually get shorter until, finally, they get so short that the cell dies
Waste products accumulate in tissue
Connective tissue between the cells becomes stiffer
The maximum functional capacity of many organs decreases
Heart and blood vessels:
The wall of the heart gets thicker
Heart muscle become less efficient (working harder to pump the same amount of blood)
The aorta (the body's main artery) becomes thicker, stiffer, and less flexible
Many of the body's arteries, including arteries supplying blood to the heart and brain, slowly develop atherosclerosis, although the condition never becomes severe in some people
It is harder for the body to control its temperature
Heart rate takes longer to return to normal after exercise
Bones, muscles, joints:
Bones become thinner and less strong
Joints become stiffer and less flexible
The cartilage and bone in joints starts to weaken
Muscle tissue becomes less bulky and less strong
The movement of food through the digestive system becomes slower
The stomach, liver, pancreas, and small intestine make smaller amounts of digestive juices
Brain and nervous system:
The number of nerve cells in the brain and spinal cord decreases.
The number of connections between nerve cells decreases
Abnormal structures, known as plaques and tangles, may form in the brain.
Eyes and Ears:
The retinas get thinner, the irises get stiffer
The lenses become less clear
The walls of the ear canal get thinner
The eardrums get thicker
Skin, nails, and hair:
Skin gets thinner and becomes less elastic
Sweat glands produce less sweat
Nails grow more slowly
Hairs get gray and some no longer grow
There is some controversy about whether or not people should continue to get screening tests for certain cancers after age 75. Variables include the person's overall health and whether or not additional life expectancy can be achieved.