Through the Years: Test Your Aging Knowledge

Osteoporosis is a painful, disfiguring and debilitating loss of bone that makes fractures more likely to occur.

Genetics, menopause and bad habits, like smoking and excessive drinking, all play a role in the development of osteoporosis. Exercise can actually help prevent this condition.

Sun exposure is not only a major contributor to the development of wrinkles but it also causes age spots and skin cancer.

Aging skin has a limited capacity to initiate vitamin D production, making vitamin D deficiency more common in older people.

As people age, their pupils get smaller and the lenses start to accumulate yellow substances, which can predispose them to glaucoma -- the product of excessive pressure inside the eyeball.

About half of adults over the age of 65 have a diminished sense of smell, which affects their ability to taste food.

The Use It and Lose It Theory of aging suggests that use, and overuse, of your organs pushes them to the brink of destruction. A poor diet, too much alcohol and cigarette smoking are thought to accelerate natural wear and tear.

People are at their tallest by their late forties and then gradually lose up to 2 inches (5 centimeters) in height by age 80.

Aging causes cartilage to lose water, making it more vulnerable to injury and often leading to arthritis.

Drinking plenty of fluids, controlling high blood pressure and keeping blood glucose levels in check helps to preserve kidney function.