40 Early Signs of Alzheimer's Everyone Over 40 Should Know

Dementia affects more than 55 million people worldwide, according to the World Health Organization (WHO)—and more than 10 million new cases reported every year. And although it can be caused by several different conditions, the WHO reports that Alzheimer's disease is by far the most common, accounting for approximately 60 to 70 percent of dementia cases. Symptoms of early-onset Alzheimer's can begin to manifest sooner than you may think: According to the National Institute on Aging, the disease can affect people under age 40, although symptoms usually appear during the mid-60s. "When the disease develops before age 65, it's considered early-onset Alzheimer's, which can begin as early as a person's 30s, although this is rare," their experts write.

The first signs of dementia may seem like normal age-related issues and be easy to miss. When it comes to Alzheimer's, however, an early diagnosis can make a big difference to your quality of life down the road, making it critical to seek screening as soon as possible. Read on for 40 early sigs of Alzheimer's disease that everyone over 40 should know.

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You used to be able to smell those fresh-out-of-the-oven chocolate chip cookies immediately, and now you hardly notice them. According to the National Institute on Aging, losing your sense of smell can be a symptom of Alzheimer's, so it's crucial to bring it up to your doctor if you notice any changes.

One of the most common changes those with Alzheimer's go through is no longer being interested in things they used to love—or no longer being interested in anything, for that matter. A 2001 study published in the Journal of the American Geriatrics Society revealed that, while disinterest is a frequent symptom among those with Alzheimer's, it's also one of the most under-recognized signs.

While everyone enjoys a mindless Netflix binge from time to time, for those with Alzheimer's, passive behavior becomes the norm, according to University of California, San Francisco Health. Someone showing signs of the disease could sit in front of the screen all day, every day, with absolutely no interest in doing anything they used to.

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Forgetting certain things—like what you ate for dinner last Thursday—is normal. When you start constantly forgetting important dates and events, however, that could be an early sign of Alzheimer's, according to the Alzheimer's Association. Pay attention to how often little things slip your mind—and if it starts to become a persistent problem, talk to a doctor about the possibility of dementia.

One of the most crushing things those with Alzheimer's go through is forgetting the names of those around them, whether it's close family members or longtime friends. And unfortunately, while this symptom of the disease can be devastating, it's also one of the more common ones.

Everyone forgets where they put their keys every once in a while, and sometimes you're so tired that you might accidentally put the milk in the cupboard. That's totally normal! For those with Alzheimer's, though, misplacing possessions and putting them in places that don't make sense happens with startling frequency, according to the Mayo Clinic.

Have you ever found yourself struggling to retrieve the word for an everyday object? Now, imagine going through that constantly. According to the Mayo Clinic, those with Alzheimer's often find themselves unable to remember what simple things are called, be it a toaster or their toothbrush.

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Problem-solving isn't an easy task for those dealing with Alzheimer's. According to the Columbia University Department of Neurology, having difficulty solving basic problems—things that are typically easy for just about anyone—is one of the key symptoms of the disease.

When someone who used to love being around others suddenly becomes a lot more socially withdrawn, it could signal a brain change often associated with Alzheimer's. Oftentimes, this shift is due to the person's awareness of the other cognitive deficits they're experiencing: They don't want to embarrass themselves by forgetting someone's name, for instance, and will therefore remove themselves from the social situation entirely.

It takes a certain skillset to make good conversation—and it takes confidence, too. But if you've always been a social butterfly and you suddenly find that you can't so much as utter a greeting to an old friend, this could be one of the early signs of Alzheimer's, as the Alzheimer's Association notes.

Similar to social withdrawal, those with Alzheimer's often avoid conversation in order to hide their mental decline.

Everyone becomes irritable at times. It's part of life. However, experiencing this emotion is also something that's been found to be a consistent early sign of Alzheimer's. In a 2015 study published in the journal Brain, researchers analyzed seven years of data and found one of the key behavior changes in Alzheimer's patients was irritability. That irritability comes from all the cognitive changes happening to the individual—and there are a lot of changes.

Depression is often accompanied by a lack of energy, trouble sleeping, appetite loss, and feelings of hopelessness, just to name a few side effects. And while the mental health disorder affects individuals of all ages, Harvard University says it could also be an early warning sign of Alzheimer's. In a 2012 study published in the journal Archives of General Psychiatry, researchers found those who are depressed—both later in life or since middle age—might have a higher risk of developing dementia.

If you find yourself getting more and more anxious over the years, it could be an early symptom of Alzheimer's disease. In a 2018 study published in the American Journal of Psychiatry, researchers found there's a link between the two. As anxiety symptoms increased in study subjects over time, so did the beta-amyloid proteins in their brain—and high amounts of those proteins are a known characteristic of Alzheimer's.

If someone is substituting unusual words into their sentences while they're talking or writing, that's a definite red flag as far as Alzheimer's is concerned. It's not uncommon for those with Alzheimer's to have trouble retrieving words or to confuse similar-sounding ones.

There's no worse feeling than getting totally lost and not knowing how to get back home—and for those with Alzheimer's, that feeling may be an everyday occurrence. This often happens to Alzheimer's patients even in places that should seem familiar, like their favorite hiking trail.

As most people get older, they tend to slow down a little bit, both physically and mentally. However, if you're losing the ability to follow plans and having trouble concentrating, meaning things take considerably longer than they used to, that could be an indication an Alzheimer's diagnosis isn't far off.ae0fcc31ae342fd3a1346ebb1f342fcb

Everyone gets confused once in a while, but those in the early stages of Alzheimer's experience the feeling more frequently than the average person. Whether it's being confused by where they are and unsure how they got there or losing track of time, it's a behavior worth monitoring.

Most people are able to tell the difference between a few minutes and a few hours. But Alzheimer's may impact a person's perception of time. "Five minutes can seem like five hours for someone with [Alzheimer's disease]," Lisa P. Gwyther, MSW, LCSW, an associate professor at the Department of Psychiatry and Behavioral Sciences at Duke University, told CBS News. "So a husband may think his wife has been gone for hours or even weeks, even if it's just been a few minutes, or he might tell his grandchild that he hasn't seen him in five years, even though he just saw him yesterday."

As Alzheimer's spreads in the brain, one issue that might pop up is a shortened attention span. Someone who used to be able to sit and have a full conversation might no longer be able to focus on just one thing for more than a few minutes or even a few seconds, according to the National Institute on Aging.

Instead of counting on those closest to them like they did before, some individuals with early Alzheimer's become distrustful of those around them. The combination of confusion and memory loss can contribute to these false beliefs.

Everyone has their ups and downs, but a sign of Alzheimer's you should never ignore is when someone has rapid emotional shifts for no reason. They could go from smiling to crying in a short period of time, according to the Fisher Center for Alzheimer's Research Foundation.

Suddenly showing aggression by lashing out at family members is common among those with Alzheimer's, according to the National Institute on Aging. Unfortunately, it can also be hard to figure out what's behind the hostility—and occasionally, those fights will even become physical.

Becoming frequently agitated could be a major red flag when it comes to Alzheimer's. As the National Institute on Aging notes, the restlessness and mental issues that plague those with the disease can be hard to deal with, and that frustration often leads to irritation over minor issues.

If you find yourself or someone else stopping in the middle of a conversation, it could be an early sign of Alzheimer's. When this is the case, the Alzheimer's Association notes it's really hard for an individual to jump back in. They have no idea how to continue on after the pause, so help them out by reminding them where you left off.

It's just not your social circle that Alzheimer's can cause you to withdraw from. According to the Alzheimer's Association, it's also common for people with Alzheimer's to no longer want to be at work, as it becomes harder to keep up with everyday tasks—even ones as simple as having conversations with co-workers.

Every month, you know exactly which bills are due and when—or at least, you used to know. In the early stages of Alzheimer's, working with numbers becomes difficult, making it hard to ensure payments are going out on time. If you suddenly struggle to remember to pay the same bills you've been paying for years, talk to your doctor about the possibility of early-onset dementia.

Something as minor as whipping up a home-cooked meal can be a struggle for those in the early stages of Alzheimer's. If someone loses their ability to follow a recipe—especially one they've made a thousand times—that might be an indication of the cognitive changes that commonly occur in the early stages of the disease.

It's happened to all of us: We zone out during a conversation and find ourselves with little recollection of what transpired during the chat. But if someone is constantly forgetting discussions they had with people—and they're unable to remember them later, even after being reminded—that's a common symptom of Alzheimer's.

Those in the early stages of Alzheimer's often begin to exhibit a perplexing symptom: dressing inappropriately for the weather. Some individuals with the condition will wear minimal clothing when it's freezing cold out, while others will dress in heavy layers in the summer, when the hot sun is beating down on them.

Even if someone was strict about keeping up with good hygiene before, that may change once they begin to showcase signs of Alzheimer's. Due to the changes in cognitive function that occur with this disease, things like taking baths or showers, changing clothes, and flossing may become difficult.

If someone is suddenly unable to play their favorite card game after years of doing so, that could be an early sign of Alzheimer's. Doing activities that involve multiple steps—like playing games—becomes increasingly hard for those with the disease.

Once in a while, you have to repeat something to make sure someone hears it. But if an individual is constantly repeating statements or questions without any recollection of having already said them, that may be an early indicator of Alzheimer's.

Even if someone has had a standing phone call with a friend for years, or knows the number of their favorite takeout restaurant by heart, they may find themselves forgetting those phone numbers if they're experiencing the changes associated with early Alzheimer's.

As Alzheimer's disease progresses, victims may start engaging in more impulsive behaviors—and that can mean everything from undressing in public to going on shopping sprees.

Though anyone is at risk of getting swindled by scammers, those with Alzheimer's are particularly vulnerable. It's not uncommon for someone with the disease to show poor judgement on a regular basis—in some cases, even by giving a large portion of their money away to people whom they've never met.

In today's world, we often do many things at once—we listen to podcasts while we work, watch TV while we exercise, and have conversations while staring at our phones. For those with Alzheimer's, however, multitasking can be extremely difficult, even in situations they once handled with ease.

You may experience sleep problems for many reasons, ranging from stress to drinking coffee too late in the day. But these disturbances can also be an early sign of Alzheimer's disease. "There's an association between Alzheimer's and sleep disturbances," Jose Colon, MD, a sleep medicine doctor, told Lee Health. "You can't make an early diagnosis of Alzheimer's based on sleep patterns, but when someone has disruptive sleep patterns, you want to keep an eye on that."

Losing your eyesight as you age might not be fun, but it's normal. On the other hand, according to Michigan State University, having trouble with depth perception—in other words, not being able to see the world around you in three dimensions (as in length, width, and height)—can be a sign of Alzheimer's.

While contrast isn't an issue for most people, it's one of the vision problems those with Alzheimer's may struggle with. And according to a 2004 study published in the journal Clinical Nutrition, this issue can make it hard for someone to differentiate a liquid from its container, like milk in a jug.

If you or someone you live with gets diagnosed with this disease, the Alzheimer's Society recommends making small changes around the home so contrasts are more obvious. (For instance, make the color of light switches different than the color of the wall so they're easier to see.)

When your memory is in good working order, you can recall most things without always having to write them down or be reminded. However, those in the throes of early Alzheimer's become more dependent on memory aids, like reminder notes, and often need their friends and family members to help them out. If you can't so much as remember to pick your friend up at the airport without an alert on your phone telling you to do so, it might be time to see the doctor.

Best Life offers the most up-to-date information from top experts, new research, and health agencies, but our content is not meant to be a substitute for professional guidance. If you have specific health questions or concerns, always consult your healthcare provider directly.