PHYSICAL CHANGES WITH AGING

Skin : With age, the skin becomes less elastic and more lined and wrinkled. Fingernail growth also slows. The oil glands gradually produce less oil, making the skin drier than before. You can slow skin aging by using moisturizer and protecting the skin from the sun with sunscreen and sun-protective clothing, such as a hat or cap.

Skin Changes with Aging

Hair : It's normal for hair to gradually thin on the scalp, pubic area, and armpits. As hair pigment cells decline in number, gray hair growth increases.

Graying Hair

Height : By age 80, it's common to have lost as much as 2 in. (5 cm) in height. This is often related to normal changes in posture and compression of joints, spinal bones, and spinal discs.

Changes in Height

Hearing : Over time, changes in the ear make high-frequency sounds harder to hear and changes in tone and speech less clear. These changes tend to accelerate after age 55.

Hearing Loss

Vision : Most people in their 40s develop a need for reading glasses as the lenses in the eyes become less flexible (presbyopia). It's also normal for night vision and visual sharpness to decline, while glare increasingly interferes with clear vision in the later years. Vision changes can affect your ability to drive safely. 

Vision Changes

Sleep : Changes in sleep and circadian rhythm occur as you age. You will probably sleep less at night, and you may not sleep as deeply as you did when you were younger. And it's more likely that you'll wake up during the night and/or wake up earlier in the morning. 

Less Sleep in Older Age

Bones : Throughout adulthood, men and women gradually lose some of the mineral content in their bones. The bones get less dense and strong. You can slow natural bone loss and reduce your risk of osteoporosis by getting regular, weight-bearing exercise (such as walking), getting enough calcium and vitamin D, and avoiding lifestyle choices that weaken bones (such as smoking). 

Changes in Bones

Metabolism and body composition :  Over time, the body typically needs less energy, and your metabolism slows. Hormone changes in the aging body result in a shift to more body fat and less muscle mass. The best approach to managing these changes is to take in fewer calories while keeping up or increasing your physical activity. Strength training is an especially good way to build or keep your muscle mass. When your muscle mass is reduced, your metabolism slows down. Building or keeping your muscle mass allows your metabolism to remain the same or increase.

Brain and nervous system. Starting in the third decade of life, the brain's weight, the size of its nerve network, and its blood flow decrease. But the brain adapts to these changes, growing new patterns of nerve endings. Memory changes are a normal part of the aging process-it's common to have less recall of recent memories and to be slower remembering names and details. You can help keep your brain sharp. Engage in regular social activity. Challenge yourself to learn and do new things. And be physically active, to increase blood and oxygen flow to the brain.

Heart and blood circulation : The heart naturally becomes less efficient as it ages, and your heart has to work a little harder during activity than it did in the past. This makes the heart muscle a little larger. 

Lungs :  In inactive people, the lungs become less efficient over time, supplying the body with less oxygen. Regular physical activity plays a key role in keeping your lungs strong.

Kidneys : With advancing age, the kidneys decline in size and function. They don't clear wastes and some medicines from the blood as quickly and don't help the body handle dehydration as well as in the past. This makes it increasingly important that you minimize the toxins, alcohol, and unnecessary medicine that you take in, and that you drink plenty of water.

Urinary incontinence : Age-related changes in the urinary system, decreased mobility, and some medicine side effects can all lead to urinary incontinence. This does not have to be part of normal aging, so talk to your doctor if urinary incontinence is affecting you.

Sexual function :  Men and women produce lower levels of hormones starting in their 50s. Men produce less sperm, and their sexual response time slows, though the male sex drive doesn't decrease. Women stop ovulating and have a number of menopausal changes linked to lower estrogen production. 

In Addition these signs also we can see in changing age:

Wrinkles and liver spots on the skin due to loss of subcutaneous fat

Change of hair color to gray or white

Hair loss

Reduced circulatory system function and blood flow

Reduced lung capacity

Reduced immune system function

Changes in the vocal cords- voice

Hearing loss.

Diminished eyesight. It becomes more difficult to read in low lighting and in smaller print. Speed with which an individual reads may also be impaired.[citation needed]

Reduced mental and cognitive ability

Depressed mood

Lessening or cessation of sex, sometimes because of physical symptoms such as erectile dysfunction in men, but often simply a decline in libido.[citation needed]

Greater susceptibility to bone and joint diseases such as osteoarthritis and osteoperosis

Memory loss is common due to the decrease in speed of information being encoded, stored, and received. It may take more time to learn new information.