The Aging Body Systems: Explaining Physiological Aging


Ever wonder what happens to the body systems as the person ages? Moreover, what changes would one qualify as part of normal or physiological aging? These are just some of the most commonly encountered questions by nurses.

While the scientific community actively seeks for the answers as to why people age, it is also helpful to determine the normal physical changes associated with aging. It holds particular relevance to nursing assessment and plan of care. Moreover, it is a vital health education topic that should be taught so the greying population and their families can institute protective measures for the points of strains in their body.

Here are the body systems and the changes they undergo while aging:


This is the system with the most obvious changes because this involves the skin, hair, and nails. The skin loses its moisture and elasticity which makes older people more susceptible to skin tears and shearing injuries. The hair loses color and the nails become thickened and brittle.

Progressive loss of subcutaneous fat and muscle tissue accompany the previously mentioned integumentary changes. As a result, muscle atrophy, “double” chin, wrinkling of skin, and sagging of eyelids and earlobes are frequently observed in older people. In older women, breasts become less firm and may sag. Tolerance to cold also decreases because of loss of subcutaneous fats.

Health promotion teaching can include maintaining healthy skin through optimal nutrition and hydration, avoiding sun damage through sunscreens and protective clothing, and preventing skin injury by avoiding strong detergents and rough textures.


Speed and power of muscle contractions are gradually reduced with age. While exercise can strengthen muscles, there would be steady decrease in muscle fibers by age 50. This condition is called sarcopenia. Also, loss in overall stature occurs with age. Kyphosis, osteoporosis, and pathologic fractures are consequently common. On the other hand, reaction time also slows with age. Decreased muscle tone further reduces reaction time. This is because diminished physical activity can decrease muscle tone.

There age-related changes are a threat to elders’ safety. The nurse must assess for factors that may increase the elders’ risk for falls and decrease their ability to perform their activities of daily living (ADLs). Importance of calcium supplements and Vitamin D should be emphasized.



All five senses become less efficient as the person ages.

As for vision, acuity becomes poor and elders have presbyopia, or the inability to focus or accommodate due to inflexible lens which can start as early as age 40. Loss of peripheral vision, atrophy of lacrimal glands, and difficulty in discriminating similar colors like blues, greens, and purples are common.

Elders over age 65 start having gradual loss of hearing, a condition called presbycusis. It is more common in men. Hearing loss is greater in the higher frequencies than the lower. Hard consonants (e.g. k,d,t) and long vowel sounds (e.g. ay) are more easily recognized while the sibilant sounds (e.g. s,th,f) are the most difficult to hear.

Older people have poorer sense of taste and smell and are less stimulated by food than the young. Sense of smell commonly declines more than sense of taste. This is the reason why changes in appetite are common in elders.

Lastly, older people become less sensitive to sensations of pain, touch, and temperature because they lose skin receptors gradually.


Respiratory efficiency is reduced with age. They are unable to compensate for increased oxygen need and are significantly increasing the amount of air inspired. Therefore, difficulty in breathing is usually common especially during activities.  Expiratory muscles become weaker so their cough efficiency is reduced and the amount of air left in the lungs is increased.

Health promotion teaching can include smoking cessation, preventing respiratory infections through handwashing, and ensuring up to date influenza and pneumonia vaccinations.



Of course, the capacity of the heart for work decreases with age. Elders’ heart rate is slower to respond to stress and slower to return to normal after periods of physical activity. Changes in arteries occur frequently which can negatively affect blood supply.

Health promotion teaching can include risk detection and reduction for cardiovascular diseases, blood pressure and cholesterol level monitoring, ideal weight maintenance, and low-sodium diet.


Age-related changes in the gastrointestinal system include reduced saliva, decreased esophageal and stomach motility, decreased stomach emptying time, decreased production of intrinsic factor, and decreased intestinal absorption, motility, and blood flow.  In addition, tooth enamel becomes harder and more brittle, making teeth more susceptible to fractures.

Health promotion teaching for elders include preventive dental care and effective oral hygiene, appropriate diet and sufficient fluid intake, regular bowel maintenance, and importance of colorectal cancer screening.


The function of the kidney decreases with age but is still able to carry out excretory functions unless a disease process intervenes. Waste products may be filtered and excreted more slowly. Therefore, nurses must include in their responsibility the effect of drugs that elders take to their kidneys.

Aside from the kidneys, the bladder makes more noticeable changes. Complaints of urinary urgency and frequency are common because the capacity of the bladder and its ability to completely empty diminish with age. It is important to note that urinary incontinence (UI) is never normal so the nurse must promptly investigate it, particularly when of new onset.

Good urinary function in elders can be promoted by sufficient fluid intake, reducing bladder-irritant foods in the diet (e.g. sugar, caffeine, spicy and acidic foods), and practicing pelvic muscle exercises.


There is gradual degenerative change in the gonads of men. However, testosterone production continues albeit decrease in number of sperms produced.

Changes in the gonads of older women result from diminished secretion of ovarian hormones. However, shrinking of uterus and ovaries go unnoticed. Other changes are obvious, like breast atrophy and reduced lubricating vaginal secretions.


Sexual response and performance also change. Both men and women take longer to become sexually aroused, longer to complete intercourse, and longer before sexual arousal can occur again. Generally, the elder man’s libido may decrease, but not disappear. Erection is less firm but can still penetrate. Ejaculation also takes longer.

People are aging every single day. Aging is human nature taking its normal course. While this is gradual in the early phase, small changes can be seen and felt. These changes may interfere with people’s acceptance of slowing and dulling capacities. Meanwhile, negative attitudes and stereotypes towards aging still remain as challenges needing to be addressed and put to rest.

Therefore, it is important for nurses to work closely with the older people in identifying risks that might inhibit them from experiencing normal and healthy aging. It is also important for nurses to assist older people in adapting to the new roles and milestones that come with aging. Moreover, nurses are instruments in making elder people feel cared for, accepted, guided, and understood.

Share this article and help us educate more people about physiological aging!

Iris Dawn is a nurse writer in her 20s who is on the constant lookout for latest stories about Science. Her interests include Research and Medical-Surgical Nursing. She is currently furthering her studies and is seriously considering being a student as her profession. Life is spoiling her with spaghetti, acoustic playlists, libraries, and the beach.

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