Body system |
18 – 50 years |
50 – 70 years |
Over 70 years |
Bones, muscles and joints |
- Bones are at maximum density during early adulthood
- After the age of 25, muscle bulk and strength start to decrease
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- Bones become weaker, particularly in postmenopausal women
- Muscle strength and bulk continue to decrease
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- Wear and tear on joints leads to increasing stiffness and pain
- Muscle strength at the age of 85 is about half the strength at the age of 25
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Digestive organs and daily energy needs |
- After the age of 30, energy needs drop by 5 per cent every decade. Decreasing energy needs cause many people to gain weight in middle age unless diet is adjusted
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- The volume of digestive fluids decreases and the intestines work less efficiently, leading to harder faeces that may require straining to expel
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- Sense of taste becomes less acute as fewer than half the taste buds remain active. Chewing and swallowing may be more difficult due to tooth loss and gum disease
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Brain and nerves |
- Ability to learn declines gradually , but life experiences accumulate and intellectual abilities continue to develop
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- Short-term memory and ability to concentrate may become less efficient
- Physical reactions become slower
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- By the age of 90, the brain has lost up to a tenth of its tissue, making it less efficient and leading to some loss of intellectual ability and physical co-ordination
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Eyes and ears |
- By the age of 40, the lenses of the eyes become less elastic, leading to difficulty in focusing on close objects
- Loss of hearing begins in the 30s
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- After the age of 50, it may be harder to see in low light or to see moving objects
- By the age of 70, it may be difficult to hear faint or high-pitched sounds
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- Ability to distinguish fine visual detail continues to decline
- Deterioration in hearing may make a hearing aid necessary
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Heart and blood vessels |
- After the age of 40, artery walls lose elasticity, causing a rise in blood pressure. High blood pressure is one factor that may potentially lead to heart disease
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- Heart muscle becomes less elastic; the heart pumps harder but is less able to respond to increased effort
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- By the age of 85, the heart is unable to support long periods of strenuous activity. As stamina decreases, elderly people become tired more easily
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Lungs and airways |
- Peak lung function is reached at 20-30 years. By 45 years, the lungs may not expand fully due to loss of some alveoli (air sacs) and weakening of rib muscles
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- By the age of 65, lung efficiency has decreased to about three-fifths of its optimum level
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- By the age of 80, the lungs function only half as effectively as the lungs of a young adult, and moderate exertion may cause shortness of breath
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Reproductive organs |
- Women usually go through the menopause at 45-55 years and afterwards are no longer fertile. In men, testosterone levels start to decline at the age of 40-50
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- In men, the prostate gland usually starts to enlarge after the age of 50; it may constrict the bladder outlet, making the passing of urine difficult
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- A decreasing level of testosterone in men reduces sexual desire. Fewer viable sperm are produced
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Urinary organs |
- Women who have given birth may have reduced pelvic muscle strength and tone, which may cause problems with urination
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- In women, falling estrogen levels also reduce pelvic muscle strength and tone. This may cause further difficulty in controlling urination
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- After the age of 75-80, kidneys become less efficient, and it takes longer for them to clear toxic chemicals from the blood
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Skin, hair and teeth |
- By the late 40s, the skin is less elastic and wrinkles appear
- Half of people over 40 years have grey hair. Some men begin to lose their hair
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- Surface of the skin becomes drier
- Hair may become considerably thinner, especially in men
- Teeth may begin to fall out
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- Skin becomes less able to regulate body temperature by retaining or losing heat, making people more susceptible to the effects of cold or hot weather
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