• “Brain fog” and “cog fog” are terms for cognitive symptoms that occur in about half of people with multiple sclerosis (MS).
• Stress and exhaustion can make MS brain fog worse.
• There are several ways to manage brain fog and support cognitive function, including by exercising, learning a new skill, and setting reminders.

Brain fog — also referred to as cog fog — is a name for the cognitive issues sometimes associated with MS. About half of people diagnosed with MS experience cognitive issues with memory, concentration, problem-solving, information processing, and visual or spatial abilities.

Although generally mild in most people with MS, brain fog symptoms can fluctuate. For example, brain fog has been found to worsen or improve depending on factors like a person’s exhaustion levels, medications, and stress. Around 5 percent to 10 percent of people diagnosed with MS have severe brain fog that can interfere with normal activities and daily life.

What Are the Cognitive Symptoms of Brain Fog?

Cognitive function — or higher brain functions — include reasoning, memory, and problem-solving. Because MS can have an impact on any area of the brain, the condition can affect almost any cognitive function.

These impacts can be mild, affecting only one or two aspects of cognitive function. In some cases, however, they may prevent you from being able to work, go to school, or attend to other responsibilities.

Brain fog commonly affects several aspects of a person’s cognition.

Memory

People with brain fog may find that their memory isn’t as sharp as before. In most cases, these memory problems involve having difficulty remembering specific information, recent events, or preplanned tasks. If brain fog affects your memory, you may find yourself frequently misplacing objects or missing appointments if you don’t set reminders.

Concentration

Brain fog can cause difficulty in concentrating, particularly when distractions are nearby. Your mind may wander when listening to multiple people talking at once. You may even experience information overload — an inability to process what’s going on in front of you — while trying to focus on one person or task in a noisy or visually distracting setting.

Remembering Words

Everyone struggles to find the right word from time to time. However, if brain fog is among your MS symptoms, you may have particular difficulty recalling words. You may, for instance, find yourself unable to come up with the word “restaurant,” instead describing it as “a place where you order food.”

Information Processing

MS can affect your ability to process information and follow a series of complex instructions, especially if you’re trying to take in a great deal of information quickly. Processing speed slows down, making it harder to keep up.

Executive Skills

Brain fog from MS can impair your executive skills, which include your abilities to plan and problem-solve. This can make it difficult to predict the future impacts of your actions or decisions.

If a person with MS experiences changes to their executive skills, a loved one will often notice these differences first. They may, for example, notice you’re making rash or unsound decisions, which can be difficult to recognize on your own.

Visuospatial Abilities

Your visuospatial abilities help you relate to and interpret visual and spatial information. Throughout the day, you’re constantly picking up on different cues to determine your place in relation to the world around you. Brain fog can impair this ability, causing you to become lost in familiar places, unintentionally bump into objects, or have trouble accurately judging your speed and distances while driving.

What Does MS Brain Fog Feel Like?

MS cog fog often causes people to become forgetful or confused or to feel generally “out of it.” As one MyMSTeam member put it, “I’ve noticed that I can zone out.”

For some people, cognitive fog involves misplacing objects. “I took out a simple bagel this morning, and I thought I set it down somewhere on the counter,” one MyMSTeam member shared. “I went to retrieve it after it was thawed, and it had vanished. I thought one of my dogs took it because they enjoy taking things off the counter, but that was not the case.”

Brain fog may also affect speech or cause difficulty recalling words. “I get my words mixed up, and pronunciation sometimes can be a struggle,” a MyMSTeam member wrote.

Brain fog can occur anywhere, and for many people with MS, the symptom is particularly concerning on the job. “At work, sometimes I’m just not ‘all there,’” a MyMSTeam member shared. “I still have to plow through it, both because I want to and because work demands it.”

Effect on Self-Esteem

People may feel embarrassed about their MS-related brain fog. In some cases, they may choose to isolate and avoid social gatherings. However, one MyMSTeam member noted the importance of spending time with others: “Let your spouse or friends talk you into going out into a social setting when your other symptoms are in a good place, and your only reason to say no is because you’re embarrassed.”

Brain fog can affect your self-esteem. “Cognitive problems are a big downer for my self-esteem,” wrote one MyMSTeam member.

Many people feel frustrated or ashamed about being unable to function the way they did before their MS diagnosis. However, it’s important to remind yourself that cognitive problems are not your fault.

What Causes Brain Fog in Multiple Sclerosis?

MS affects brain health in several ways, resulting in brain fog. In some cases, medications used to treat MS can contribute to cognitive changes.

Cell Damage

Multiple sclerosis damages the brain’s nerve cells and myelin (the coating that protects nerve cells). MRI scans have tied the severity of brain fog to the extent of demyelination (myelin damage) within the brain.

The location of the damage can dictate the specific symptoms you may experience. For example, damage to the part of the brain responsible for speech can impair your verbal abilities.

Brain Lesions

Brain fog has also been associated with lesions in the brain resulting from MS. Neither the type of lesions a person has nor their location seems to influence a person’s brain fog. The overall number of lesions, however, does matter: The more lesions a person has, the more severe their brain fog will likely be.

Relapse

Relapses of MS may worsen brain fog. One study followed people with stable MS, people with MS who were relapsing, and people with no MS diagnosis. Researchers found that the people undergoing relapses scored lower in cognitive tests.

Certain Medications

Some medications commonly prescribed for MS can contribute to brain fog. If you’re experiencing new or worsened cognitive problems, you should ask your doctor whether any of your prescriptions could be the cause.

Ways To Manage Brain Fog

Fortunately, there are techniques for managing and living productively with brain fog. Following are some tips from researchers and MyMSTeam members.

1. Get Some Exercise

Doctors used to advise against exercise for people with MS, believing physical activity could worsen symptoms or cause the condition to progress.

Today, it’s understood that exercise can have tremendous wellness benefits for people with MS. Although there is no evidence that physical activity can slow the condition’s progression, exercise has been shown to help improve mood.

People with MS have found water exercises, Pilates, tai chi, stretching, and yoga to be great forms of physical activity. Ultimately, the right exercise routine to support your physical and emotional wellness will depend on your overall health and personal preferences.

Your doctor is your best resource for determining which exercises will be safest and most beneficial for your well-being. Always talk to your doctor before beginning a new exercise routine.

2. Find Ways To Relax and Rest

Brain fog can feel worse if you’re feeling especially tired or stressed. Meditation has demonstrated significant benefit for people with MS. Resting, deep breathing, and positive affirmations may also help.

“My symptoms get a lot worse when I’m exhausted. I need to lie down frequently. It’s the only way I know to relax at all,” advised a MyMSTeam member. “If you can’t lie down, sit down and focus on your breath. Deep, rhythmic breathing relaxes the brain. Pace yourself, use calming self-talk (e.g., ‘This will pass. It's going to be OK.’). It helps.”

3. Make Associations To Aid Memory

Memory loss can be a frustrating symptom of MS brain fog. Building connections or associations can help. For example, you might try connecting two activities, such as taking your medication with your first glass of water in the morning. This practice can help reinforce the habit: If you do one activity, you’ll be more likely to think of the other and do it, too.

If you have trouble remembering names when meeting new people, associate them with someone you know who has the same name or with a word that sounds like the name.

Read about more ways to manage memory problems.

4. Use a Calendar and Set Reminders

Brain fog can cause you to forget appointments, special occasions, and daily responsibilities. Calendars, alarms, and to-do lists can help ensure you stay on top of your tasks.

“I have a calendar on my computer and keep a calendar that tells me birthdays, anniversaries, appointments, and any other things I have to remember. I check it each day. It’s on my phone, too,” one MyMSTeam member wrote. “I [also] put alarms on my phone to remind me to do things, like call my brother for his birthday, go to a doctor’s appointment at 4, give my dog his flea meds, remember to buy bread, etc. It may seem stupid to some, but they don’t have MS.”

5. Try Learning Something New

Sometimes, training one part of your brain can help you strengthen your overall mental health. One MyMSTeam member found that their brain fog improved after they began learning a new language. “I’ve started learning Welsh, as I had heard that learning another language keeps the gray matter [of the brain] healthy,” they wrote. “Sure enough, after five weeks, I’m actually remembering what I learned — plus remembering a whole sentence both in Welsh and English. Try something new. It’s working for me, and I’m so pleased that I have typed all this!”

6. Talk to Your Doctor

Your neurologist should be able to connect you with specialists who can help you manage your brain fog or restore some of your lost cognitive function. The first step may be cognitive testing to identify problems. Your doctor may refer you for cognitive rehabilitation, a type of therapy that’s been shown to improve cognitive functioning.

Get Support From Your Team

MyMSTeam is the social network and online support group for those living with multiple sclerosis and their loved ones. On MyMSTeam, more than 195,000 members gather to share experiences and support each other.

How does MS brain fog affect your daily life? Do you have any tips for managing it? Share your experiences in the comments below or by posting on your Activities page.