Could you have brain fog? How to tell and what to do.

That fuzzy, sluggish feeling you get sometimes could be a sign of something more serious. Here’s what you need to know.

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Have you ever experienced the fuzzy sensation like your brain doesn’t feel as sharp as usual? Maybe you struggle to recall a conversation. Or you can’t grasp the right word.

When this happens occasionally, you probably don’t give it a second thought. But when your brain feels like it’s lost in a dense fog all the time, you may start to worry. What you may be dealing with is brain fog.

What brain fog feels like can vary from person to person. But overall, it’s a general sense that your brain isn’t working as it should.

You may have read about it recently as one of the lingering effects of the COVID-19 virus. One study found that 22% of people who had COVID-19 showed cognitive impairment, such as brain fog, three months after their illness. Brain fog can also be caused by chronic disease, stress, depression, cancer treatments, and many more factors.

Let’s take a closer look at brain fog, what might be causing it, and what you can do about it.

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What exactly is brain fog?

Brain fog is a term that describes a variety of cognitive issues that seem very real to you but might not be easy for others to see and understand, including doctors. And these cognitive issues tend to be difficult to explain and measure.

“Patients have a hard time being really specific with what’s changed, because it’s just hard to monitor,” says Leigh Charvet, Ph.D. She’s a professor in the department of neurology at New York University Grossman School of Medicine. “We haven’t been able to measure it reliably yet.”

And here’s the baffling part: Charvet notes that someone with brain fog may even do well on cognitive tests, even though in the real world their brain may not function properly throughout the day.

Diane Von Ah, Ph.D., a registered nurse and distinguished professor at the Ohio State University College of Nursing, has studied brain fog through a specific lens: cognitive impairment that can result from chemotherapy. This is a powerful type of drug treatment for cancer patients.

She points out that you can actually see structural and functional changes in the brains of people who have undergone chemotherapy in brain scans. So while the symptoms of brain fog can be vague and all over the place, they may stem from real changes in the brain.

What causes brain fog?

The simple answer: Experts aren’t entirely sure. It’s often a symptom of something else, such as a viral infection or chemotherapy treatment.

One root cause of brain fog could be inflammation, says Von Ah. Certain conditions can cause lots of inflammation, resulting in damage throughout the body, including the brain. Inflammatory conditions include:

  • Autoimmune diseases. These are conditions in which the body’s immune system attacks healthy parts of your body. Some examples:
    • Crohn’s disease, which causes chronic inflammation in the intestines
    • Fibromyalgia, which causes pain and fatigue throughout the body
    • Lupus, which can cause inflammation in many parts of the body, such as your joints, blood cells and organs
    • Multiple sclerosis, which causes damage to nerve cells
  • Cancer
  • Infections
  • Stress

This damage could interfere with your cognitive and executive function or your ability to carry out day-to-day tasks.

Another possible cause? Your body simply can’t maintain cognitive functions if it’s busy dealing with another problem, such as an underlying illness. When something else is wrong, that drains your body’s resources needed to sustain normal brain functions, Charvet explains.

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Other suspected causes or triggers of brain fog include:

  • Certain medications
  • Depression
  • Chronic pain
  • Hormonal changes, such as those that occur during pregnancy or menopause
  • Sleep problems
  • Vitamin and mineral deficiencies
  • Heart surgery

How do I figure out if I have brain fog, and when should I tell my doctor about it?

Since brain fog is difficult to define and track, it’s not super easy to diagnose either. Symptoms tend to be hard to pin down and can vary from person to person. Some of the more common symptoms include:

  • Cloudiness in judgment or difficulty making decisions
  • General tiredness and fatigue
  • Losing your train of thought
  • Memory problems, such as remembering names, places, or words; or forgetting meetings and appointments
  • Slow reaction times
  • Trouble focusing and keeping attention

You’ve probably experienced the occasional bout of brain fog, which can result from minor and short-term issues. Maybe you have jet lag after a flight across the country. Or your mind feels foggy after you take certain over-the-counter medications, such as ones for seasonal allergies. These episodes clear up quickly.

But if brain fog persists or begins to interfere with aspects of your life, you might want to talk to your doctor about it. And while your doctor can’t write you a prescription for something that will “cure” brain fog, they can often treat what’s causing it.

“Sleep issues, depression, pain — these things are very treatable,” says Von Ah. Addressing these issues may help you think more clearly.

Another tip: Pay attention to when you notice brain fog coming on and whether it’s connected with the onset of other symptoms of an illness. This can help your doctor better understand what’s going on, says Charvet.

What steps can I take on my own to manage brain fog?

There are brain-healthy habits that may help you think more clearly. Try adding these strategies to your daily routine:

  • Practice mindfulness exercises such as meditation or writing in a gratitude journal.
  • Eat a healthy diet.
  • Get seven to eight hours of sleep a night.

Another important step you can take? Regularly exercising your brain, whether that’s doing a challenging jigsaw puzzle or learning to play a musical instrument.

That might also include doing an online brain training program like BrainHQ. The site’s brain exercises, designed by leading scientists and proven to be effective, can help boost your ability to focus and make decisions more quickly. If you have a Medicare Advantage plan, check your eligibility for a BrainHQ membership at no additional cost. 

So even though brain fog may be hard to define and diagnose, you can still take an active role in preventing it. If your symptoms don’t go away, talk to your doctor. They’ll be able to pinpoint the underlying cause and come up with a treatment plan.

Additional sources
Study on COVID and cognitive impairment:
Brain, Behavior, and Immunity
Defining brain fog: Harvard Health Publishing
Causes of brain fog: Oregon Health and Science University
Symptoms of brain fog: Cleveland Clinic