Did you misplace your keys last week? Or forget the name of the man who bought the house across the street last month, but it's "on the tip of your tongue"? If so and you're older, you may be afraid you're developing Alzheimer's disease. Alzheimer's usually strikes senior citizens 75 years of age and older, but even young people fear the dreaded disease.

"I even had patients in their 20s with such fears," says retired neurosurgeon Dr. Russell Blaylock. Usually, there's no cause for worry.

"Although the newer thinking about so-called age-related memory loss is that a large number of these individuals will go on to develop full-fledged Alzheimer's disease, I think this is overblown," Blaylock tells Newsmax Health.

"If you forget a name or some other bit of information, but a few minutes or hours later remember it, then all is well," said Blaylock, author of The Blaylock Wellness Report.

What are normal age-related memory lapses? Below are 10 examples of worrisome behaviors that the Alzheimer's Association says usually mean you're fine — just perhaps getting older.

• Forget a name or an appointment. If you remember them later, that's normal. But if you forget recent information or forget important dates or events, you may have a problem, especially if family members complain that you ask the same questions over and over.

• Make mistakes in your checkbook or miss paying a bill. Everyone makes occasional math errors and misses paying a bill. However, if bills go unpaid for months and you have other difficulties, such as following a favorite recipe, you have a problem.

• Need help recording a television program. Perfectly normal, say the experts, but it's a problem if you have difficulty completing familiar tasks, like not remembering the rules to a game you've played for years or if you lose your way while driving to a familiar location.

• Temporarily forget the day of the week. Who doesn't get occasionally confused about which day of the week it is? But Alzheimer's patients lose track of seasons and even the year, and often don't understand how much time has passed. They can even forget where they are.

• Vision problems. While vision changes due to cataracts are normal, difficulty reading as well as judging distance and determining color or contrast could be an indication of Alzheimer's.

• Searching for the "right" word. Perfectly normal, but those with Alzheimer's may have trouble following a conversation, stop suddenly in the middle of a sentence, repeat themselves, or call things by the wrong name.

• Lose your keys. Losing your keys is common — and normal — as long as you can retrace your steps to find them. But if you're developing Alzheimer's, you may not be able retrace your steps. You may also put things in the wrong place, like putting the milk in the linen closet, and even accuse others of stealing.

• Make a bad decision. We all occasionally use bad judgement, but people with Alzheimer's may give large amounts of money to others, even to strangers like telemarketers. They may also skip bathing and don't dress as sharp as they used to.

• Feel tired of work, family, and social obligations. This, too, is normal, says the Alzheimer's Association. However, if a person starts avoiding hobbies and social activities, and maybe can't remember how to do a favorite pastime, such as forgetting how to play the piano, Alzheimer's may be the culprit.

• Get upset when a routine is disrupted. Developing specific ways of doing things is normal when we get older, and so is becoming irritable when routines are disrupted. But Alzheimer's victims can be confused and depressed, and they may feel more fearful or anxious when they are out of their comfort zone.

One particular sign should be a cause for worry, says Blaylock. "Losing one's sense of smell is a good sign of Alzheimer's." Scientists at Canada's McGill University studied people at high risk of developing Alzheimer's, and found that those who had the most difficulty identifying odors had the most biological markers for the disease.