Is your forgetfulness actually an early sign of Alzheimer's?
Credit: Aad Goudappel

Have you been more forgetful than normal lately? Don't worry—most memory issues, especially in young and middle-aged women, are not signs of dementia or Alzheimer's. Have you been stressed? Increased absentmindedness could simply be due to anxiety and might subside when the stress does. Also, some forgetfulness (drawing a blank on names, losing your keys or glasses) is common and expected as we age. That's because parts of our brains slowly start to decline in volume, and blood flow to the brain can also decrease.

The time for concern is if you find yourself losing track of the important stuff—you're getting lost in familiar places, having trouble following directions or becoming confused about dates and times of big life events—possibly making it difficult for you to go about your life. Some people, mainly seniors, with this level of mental decline have what's called mild cognitive impairment (MCI), meaning they struggle with memory more than normal for their age, but their symptoms are not as severe as those of people with Alzheimer's disease, and they're able to carry out their usual daily activities. While folks with MCI are at higher risk of developing dementia later on, some people never get much worse. (There are no proven methods to reverse MCI, but some research suggests that healthy lifestyle choices, like exercising regularly, may help slow cognitive decline.)

With early-onset Alzheimer's, which is when symptoms start before age 65, serious memory loss and confusion occur over time, potentially making it impossible to function day to day without assistance. The condition is rare, however, accounting for only about 5 percent of Alzheimer's cases. Memory problems can also be a side effect of certain medications or a symptom of a vitamin B[subscript 12] deficiency, thyroid problem or brain tumor.

Chances are, there's no reason for concern. But if your forgetfulness is interfering significantly with your ability to function normally, you should see a neurologist, who can administer certain scans or order cognitive testing to see if anything seems amiss.

Health’s medical editor, Roshini Rajapaksa, MD, is assistant professor of medicine at the NYU School of Medicine.