To most the elderly, ageing is most manifest on the skin and hair. Public concern over skin wrinkles, changes in skin pigmentation, hair loss, and graying hair is mainly related to self-image. However, gerontologists think that these signs may serve as “biomarkers” for ageing and there is only some correlation between these signs of ageing and well-being. There are some distinct structural and functional changes in the skin occur with normal ageing. They include wrinkling and sagging of skin, loss of resilience, diminished absorption, altered thermal regulation, decreased sensitivity to pain and pressure, decreased inflammatory response, lowered protection from UV light, and delayed healing. Graying of hair is a normal ageing process which normally begins in the fifth decade. Graying appears first at the temples and gradually involves the whole scalp and then the beard and body hair. Furthermore, there is a reduction in the number of hair follicles per inch of skin accompanies ageing and it leads to a slower hair growth and a narrowing of the hair diameter.

1. Changes in Heart
With ageing, the heart pump becomes less efficient, especially on exercise. Firstly, the muscle wall of the heart becomes thickened. Secondly, the heart rate does not increase so much with exercise and stress. These limit the capacity of older people to perform strenuous exercise. However, diseases of the heart can adversely affect the heart function much more than normal ageing.  
2. Changes in arteries
Calcium & collagen deposits in the outer walls of the arteries with ageing, the thickened arteries, decreasing their elasticity and therefore their ability to accommodate increase in blood flow during exercise. Moreover there is steady rise in blood pressure with age. These factors make older people vulnerable to stroke disease.

The bone mass peak reach at 25-30 years old, start to decrease some about age 39 slowly and the loss accelerate after approximately age 50, with menopause in women. These losses are multifactorial and involve age-related changes (reduced Ca absorption, increased bone resorptive activity and decreased osteoblast bone formation), physical inactivity, hormone deficiency, and nutritional insufficiencies. Hence, adequate calcium intake and physical activity is important in the elderly in preventing the osteoporosis.

As we age, the connective tissue and muscles involved in expansion and contraction of the bladder weaken. In normal adults, the bladder can store more than 400~500ml urine in female and 350~400ml urine in male. The ability to store urine is reduced in the older person, resulting in more frequent episodes of bladder voiding. The efficiency of emptying the bladder is reduced in older persons, while the perception of the need to void is also reduced.

Renal function declines with age. Approximately 50% the nephrons are lost between the ages of 30 & 70 years. Reduction in renal function leads to impaired homeostasis, makling the elderly person much more vulnerable to the effects of dehydration and water overload. Ciradian rhythms of water excretion are lost leading to nocturia. Many drugs are excreted by the kidney. Usual adult doses may lead to drug toxicity.

With ageing, elasticity of the lungs declines, the chest wall becomes increasingly stiff as a result of kyphosis and calcification of costal cartilages. These structural changes lead to reduced capacity in ventilating of the lungs. This predispose them to chest infection and reduced capacity to perform physical exercise.

The weight of the brain decreases significantly with normal ageing, with ageing, the awareness of pain, touch, temperature, joint position and vibration sense is reduced; control of posture and balance also declines with age, so that older people are more prone to falls. These can due to number of changes in brain function:

• Intelligence: A person’s IQ peaks between age 18-25, followed by a slow decline.
• Memory: With ageing, short-term memory and retrieval mechanisms are impaired.
• Sleep is less restful, less deep and interrupted.

The secretion of saliva decreases with ageing and it leads to dryness of mouth and discomfort in talking and chewing for the older person. Swallowing may be affected by disease processes rather than by old age. There is no major change in function of stomach except difficulty in digesting meats due to weakening of its muscles and change of gastric juice contents.
The major functional change in the small intestine is the reduced absorption of some nutrients (e.g. calcium, iron, lactose, Vitamin D) while the absorption of some highly lipid soluble compounds including Vitamins A & K and cholesterol is well maintained. There is a reduction in lubricating mucus and weakening of muscles occurred in large intestine which affects the transit of waste into the rectum. The anatomic changes of pancreas have no essential impact on its function.
The mass of liver reduces and the hepatic blood flow falls with age. The clearance of drugs was affected. The function and anatomy of gall bladder are well preserved in old age. But enhanced cholesterol formation gives the bile with a raised cholesterol saturation and tendency to develop gallstones.

Hormones are major contributors to homeostatic regulation in the body. The effects of ageing on the endocrine system are illustrated below by indicating the changes in three major hormones, namely sex hormones, thyroid hormone and insulin.
Sex Hormones
The menopause in women generally occurs at about age 50 on the average. During menopause, there is a decline in production of estrogen (female sex hormone) which accelerates bone loss and hardening of artery.
Sex Hormones
The thyroid gland shows structural changes (e.g. decrease in volume & increase in connective tissue) in the aged but the serum levels of thyroid hormone and thyroid-stimulating hormone remain constant into later life. The function of the thyroid gland appears to remain adequate with ageing.
Insulin
Insulin plays an important role in regulating the blood glucose level. Insulin levels in the blood are ordinarily stable with age. Glucose tolerance gradually declines in older persons as a result of decrease in insulin sensitivity in the aged. Generally, the fasting blood sugar is not significantly influenced by age except for the individuals with diabetes or obesity. Sedentary lifestyle may be implicated in poor glucose tolerance. Appropriate exercise programs and diet control may improve glucose tolerance even in advanced age.

From age 30 to age 80, muscle mass decreases in relation to body weight by about 30-40%. Strength also decreases, from age 30 to age 80 a person’s handgrip strength decreases 60%; however, physical activity plays an important mitigating role: people who remain physical activities do not appear to lose any strength. Preservation of muscle mass is important in maintaining function. Resistance exercises is the only effective method in reducing the age related decline in muscle function.