Healthy aging quiz: What's normal aging and what's not?

About half the adults age 65 and older in the United States have most of their natural teeth. And the number of adults with natural teeth continues to grow, thanks to fluoride in drinking water and toothpaste, advances in dental care, and improved oral hygiene. Don't accept cavities and gum disease. You can improve your chances of keeping your teeth as you age by brushing and flossing daily, and by seeing your dentist every six months.

As you age, your internal clock — your circadian rhythm — adjusts, making you sleepy earlier in the evening. As a result, you might find that you go to bed earlier and wake up earlier. You'll likely need the same amount of sleep as you age, but getting those same quality sleep hours is more difficult because you don't sleep as soundly.

As long as you're waking rested and refreshed, your changing sleep schedule shouldn't be a cause for alarm. If you're having trouble sleeping, it could be something more than typical aging changes. Insomnia is the most common sleep problem, no matter what your age. Stick to a regular schedule — wake up and go to bed at the same time each day. Avoid napping more than 20 minutes during the day. Exercise can help you maintain your sleep schedule. Also try sleeping in a cool room, using eyeshades and reducing or eliminating the amount of caffeine, alcohol and other liquids you consume in the evening hours.

Though memory-related diseases, such as Alzheimer's, are more common in older adults, they aren't inevitable. Many older adults maintain sharp minds. Occasional memory lapses are common, but if you find you're misplacing your keys or forgetting names and appointments more frequently, talk to your doctor about your concerns.

Depression and anxiety can also cause memory problems. If you feel sad, lonely or worried, you might find it harder to concentrate. Talk to your doctor or a counselor about your feelings.

In the meantime, keep your mind fit and agile by giving it a workout. Exercise your mind with a new hobby or skill — take up that musical instrument you never had the time to try. Or try word games, such as crossword puzzles.

Many people with chronic joint pain assume their aches are just part of growing older, so they don't see their doctors. Pain, swelling and stiffness in a joint that lasts for more than two weeks may be a sign of arthritis. See your doctor if joint pain bothers you. Identifying and treating arthritis early may mean less pain and disability in the future.

At least one in every 10 people age 65 and older has urinary incontinence, and it's even more common in older women. But it isn't caused by aging. Instead, urinary incontinence can be caused by a number of conditions, such as urinary tract infections, weakened bladder muscles or certain medications.

Most causes of urinary incontinence are treatable. Talk to your doctor about your concerns, especially if loss of bladder control is keeping you from enjoying everyday activities.

While it may be a common-held belief that getting older means being less happy, depression isn't caused by aging. Everyone feels sad from time to time, but feeling hopeless and worthless is a sign of something more serious. Help and treatments are available. Talk to your doctor about your feelings.