Is That Brain Fog Holding You Back—or Is There a Hidden Health Crisis You’re Ignoring?

Ever find yourself mid-chat, completely blanking on a name or that elusive word—yeah, “that thing”—and start wondering, “Is my brain just on a vacation, or is something more serious brewing?” You’re not alone. That cloudy, foggy-headed feeling, where birthdays slip by unnoticed and conversations turn into a hazy blur, is something most of us have wrestled with at some point—especially as the years pile on. It’s pretty common, too; a hefty 28 percent of adults admit to juggling bouts of slower thinking and concentration struggles. But here’s the kicker—not every haze signals the onset of Alzheimer’s or cognitive doom. Sometimes, it’s just your body hoisting a tiny white flag, waving for a break or a tune-up. Brain health doesn’t exist in a vacuum—it’s intimately tied to how well we treat our bodies, and those daily lifestyle nudges can either sharpen your focus or plunge you into a mental fog. So let’s unravel what’s normal, what’s a red flag, and when it’s time to get some expert eyes on those mental glitches. Ready to clear the fog? LEARN MORE

YOU FEEL CLOUDY, unfocused, maybe even a little detached. You’ve missed a birthday, forgotten a name, or spaced in the middle of a conversation—and you’re starting to wonder if these are signs of a serious health concern.

A bout of brain fog is fairly common, especially as we get older. According to one large study, 28 percent of adults report having experienced symptoms like slower thinking, confusion, and trouble concentrating at some point. It’s easy to jump to worst-case scenarios, but such episodes aren’t always evidence of Alzheimer’s or cognitive decline. Sometimes, they’re just your body waving a white flag.

“Brain health is a direct result of body health,” says Alexander Billioux, MD, chief medical officer for government programs at United Healthcare. In other words, brain hiccups can be triggered by a range of physical or lifestyle stressors, from something as simple as skipping a meal or skimping on sleep, to fighting a recent or ongoing illness.

Persistent or worsening symptoms, however, can occasionally point to deeper issues like depression, mild cognitive impairment, or even early signs of dementia. Understanding what’s behind these mental glitches is the first step. Here’s how to spot what’s normal, what’s not, and when and how to get help.

Mental Glitch: Forgetfulness

BLANKING ON THE name of that guy down the street or even the word for that thing—you know, that thing, it’s on the tip of your tongue—is normal human behavior. “Ironically, it seems to become even more likely in stressful environments,” Dr. Billioux says—like, say, a reunion or extended family BBQ where you’re expected to remember a lot of names.

Spacing on what day it is every now and then is likewise a regular part of normal aging. But forgetting to show up to important events, or struggling to remember the right words more often than other people your age, could point to something called mild cognitive impairment (MCI). MCI can sometimes be an early sign of a more serious memory issue, such as Alzheimer’s disease or other forms of dementia.

“Vascular dementia, for example, occurs after strokes or mini-strokes, when you’re not getting enough blood to the brain,” Dr. Billioux says. “People start to have difficulty with speech, because the speech or recall centers of the brain are affected.” So if you’re having trouble holding a conversation, or friends are saying things like, “You just asked me that question five minutes ago,” with increasing frequency, it could be time to check in with your doctor.

Mental Glitch: Trouble Concentrating

THAT CLOUDY, SLUGGISH feeling—when your thoughts feel delayed or just out of reach—is the hallmark of brain fog. It often strikes when you’re tired, hungry, sick, or stressed. “A surge of adrenaline from the body’s stress response actually sharpens your senses in the short term,” Dr. Billioux says. “However, if that stress hormone lingers for too long, your body stops responding as much to it, and that can cause persistent brain fog.”

Longer-lasting brain fog is associated with a number of conditions, ranging from migraines to kidney disease to long Covid. So when does mental sluggishness cross the line into cognitive decline? “If you suddenly and persistently cannot do a basic task that you’re normally able to do, that’s something that warrants being looked at right away,” Dr. Billioux says.

Mental Glitch: Confusion with Routine Tasks

HAVING TROUBLE WITH everyday activities? Brain fog can also take the form of visuospatial challenges, like knocking over your toothbrush as you reach for the faucet or getting lost while driving. Before you chalk it up to anything else, consider an eye exam. “As we get older, our vision starts to decline, and that can be the cause of many little things like difficulty driving at night, or having to read the same sentence over and over,” Dr. Billioux says. “It might not be brain fog at all, but rather an issue with your eyes.”

On the other end of the spectrum, some forms of dementia and mental-health disorders can cause visual changes along with confusion, including hallucinations. When you’re frequently misplacing things in odd places (wallet in the refrigerator, for example) or getting lost in familiar surroundings—coming home from the grocery store, or finding the bathroom at night—that’s cause for concern and a call to the doctor.

IF YOU DON’T have the energy for a social life right now, you’re not alone (figuratively, anyway): JOMO is having a moment. But if you’re feeling less “joy of missing out” and more lonely or depressed, it’s worth taking a look for potential causes of your sudden introversion. Persistently low mood that interferes with your daily life is a major symptom of depression, which in turn can contribute to problems with memory and concentration.

Or maybe you’re shying away from social situations because of your ears, not your brain. “It’s frustrating not to be able to hear the person you’re talking with, and sometimes it can even cause confusion. Hearing loss is more common as we get older, and so is serum impaction—which is just earwax in the ears,” Dr. Billioux says. “Telling your doctor that you’re having difficulty hearing could result in a quick fix where they simply remove that earwax, and that can significantly improve brain fog.” And if that doesn’t improve your hearing, it might be time to have it checked.

Mental Glitch: Irritability

WHEN YOU’VE LOST your keys (again), played dropsy with your morning coffee, and missed a lunch meeting, it’s easy to see how cognitive changes can morph into mood changes. “Frustration can manifest into being more irritable with other people,” Dr. Billioux says. Like other mental symptoms, a short fuse can result from a recent illness, a bout of high stress, or a rough night of sleep. Another source of agitation could be your diet. “The brain metabolizes carbohydrates, so people on an extremely low-carb diet may experience brain fog and irritability,” Dr. Billioux says.

When lashing out is a symptom of a more serious condition, like Alzheimer’s or other forms of dementia, it often shows up later, following more obvious signs of cognitive decline. “Alzheimer’s is caused by plaques that build up in the brain over time, and a lot of that buildup can happen in the front part of our brain, which is where much of our personality is,” Dr. Billioux says. “So as Alzheimer’s progresses, those plaque densities increase, and people can become more irritable and combative.”

When and How to Get Help

IF THE COGNITIVE changes you’ve been experiencing are strong, sudden, and persistent, now’s the time to check in with your primary care provider. Tell the doctor when and how you first became aware of the forgetfulness, trouble concentrating, or mood changes, and how the symptoms are impacting your day-to-day life. This is also one more reason to keep up with your annual wellness visits, even when you feel fine: “Your PCP will have seen you over the years, can compare against your past records, and can tell you whether they’ve noticed changes in you as well,” Dr. Billioux says.

Of course, when you’re feeling off, making and keeping a doctor’s appointment can seem daunting; minimizing the problem in your head is a lot easier. “Our brains are really good at explaining away odd things, including our own behavior,” Dr. Billioux notes—which is why he recommends bringing a friend or family member to the appointment with you who can help confirm or clarify what’s been going on. From there, your doctor can suggest testing or treatment for routine health issues that could be causing your brain fog, or connect you with the right specialist.

How to Keep Your Brain Sharp

THE BEST WAY to protect your brain is to take good care of your body. Getting a solid eight hours of sleep a night, eating nourishing foods (including healthy carbohydrates), screening for hearing and sight issues on a regular basis, and doing 30 minutes of heart-pumping exercise five times a week will all reduce the likelihood of brain fog.

Exercising your brain helps, too—such as reading, doing puzzles, and other problem-solving activities. “People are working later in life these days, and while that helps us diagnose higher rates of dementia—because people in their work environments notice those kinds of signs earlier—it’s also helping stave off more brain disorders,” Dr. Billioux says. In other words, the more you’re actively using your mind, the healthier it will stay.