What’s The Difference Between Brain Fog & Being Tired? Here’s How To Tell If Your Confusion Is A Sign Of Something More Serious

Andrew Zaeh for Bustle

Brain fog can be a frustrating experience where mental clarity and focus go out the proverbial window. Brain fog can run along a spectrum of mild mental fatigue, to serious problems concentrating and can interfere with your ability to complete daily tasks. For anyone who's ever gone to work after a night of less than stellar sleep, this may be a familiar feeling. But what if you're still unable to concentrate after repaying your sleep debt?

"There's no question that being overtired makes it temporarily harder to concentrate," Mary Shomon, Thyroid Refresh advisory board member, tells Bustle. "Brain fog, however, is different in that it often doesn't improve with a good night's sleep."

"Brain fog isn't a single diagnosis, but more the resulting condition from a variety of causes," Dr. Darria Long Gillespie, a Harvard- and Yale-trained ER doctor and author of Mom Hacks, tells Bustle via email. "While sleep deprivation can make it worse, we often see it in systemic conditions that cause the underlying problem ... the key solution is to target and treat the primary condition."

According to Healthline, brain fog can cause memory problems, trouble focusing, difficulty concentrating, and an overall lack of mental clarity. While sleep deprivation can be the culprit for fuzzy thinking the next day, other conditions should be ruled out if your brain fog persists over time. Healthline further notes that while chronic mental fatigue can interfere with getting daily tasks done, resolving it is possible once any underlying causes are addressed.

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Medical News Daily reports that brain fog can affect functions like the ability to communicate, visual and spatial awareness skills. Organizational, planning, and problem-solving abilities can all be seriously affected by brain fog, too. Conditions such as multiple sclerosis (MS), chronic fatigue syndrome (CFS), fibromyalgia, and depression can all contribute to brain fog. Hormonal changes like those from perimenopause, menopause, or hypothyroid can also be a factor, as can iron deficiency anemia, Medical News Daily further states. Harvard Health also notes that brain fog can be a side effect of some medications and low levels of vitamin B12.

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Howard Franklin, MD, Vice President of Medical Affairs for Salix Pharmaceuticals, tells Bustle that recent studies also show that brain clarity is significantly impacted by the health of the gut microbiome, and that certain digestive disorders can also play a role in how sharp our mental processes are. "Brain fog refers to a specific group of neurological symptoms which can be the result of many things ... among them a dysfunction in the bacteria that line our intestines," Dr. Franklin says.

So, how do you know if your brain fog is due to fatigue, or instead points to something more serious? Harvard Health notes that if you’re noticing ongoing brain fog and cognitive problems that don’t resolve with rest — especially if you’re suddenly needing more rest than usual — see your doctor as soon as you can. While your brain fog isn’t necessarily cause for alarm on its own, it can be an important symptom to take note of. Your doctor can examine you to determine if some underlying issues might be at play, and once you’ve identified the cause of your brain fog, you can take steps to resolve it, ASAP.