Brain fog: causes and what helps
When your thoughts feel slow and cloudy, it’s not a personal failing. Brain fog has real causes, and there are real ways to work around it.
By the numbers
How often brain fog comes up with common causes.
Common causes
Sleep & daily life
What is brain fog?
A name for cloudy, slow thinking, not a disease.
Brain fog is not a medical condition on its own. It’s a term for a group of symptoms that affect thinking, like trouble focusing, remembering or finding words.
Brain fog can follow an illness, come with a health condition, or be a sign of something else going on, like poor sleep or stress. Finding the cause is the first step to feeling clearer.
How it can feel
Like thinking through cotton wool.
People describe brain fog in many ways: like wading through mud, thinking through cotton wool, or having too many browser tabs open.
Common experiences
- Confusion
- Feeling mentally exhausted
- Forgetting things more than usual
- Losing your train of thought
- Slower thinking and reactions
- Struggling to find the right word
- Trouble concentrating or paying attention
Brain fog can make everyday things harder, like following a conversation, reading a page, making decisions or keeping track of appointments.
Everyday causes
Sleep, stress and food can all cloud thinking.
Often, brain fog comes from things in daily life. These are worth checking first, because small changes can make a big difference.
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Not getting enough sleep can cause problems with learning, focusing and reacting. People who are short on sleep may struggle to make decisions, solve problems and remember things.
Sleep-deprived people also take longer to finish tasks, react more slowly and make more mistakes.
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Stress is a common cause of brain fog.
When your mind is full of worries and to-do lists, there’s less space left for focusing and remembering. Long-term stress can also lead to burnout, where brain fog is common.
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Poor nutrition can contribute to brain fog. So can low blood sugar, including in people living with diabetes.
Regular, healthy meals help keep your energy and focus steadier through the day.
Health causes
Conditions and life stages where fog is common.
Brain fog is also linked with many health conditions and life changes. Tap each one to learn more.
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Difficulty thinking or concentrating, sometimes called brain fog, is listed by the CDC as a common symptom of long COVID. Symptoms can get worse after physical or mental effort.
In June 2023, about 6% of U.S. adults had long COVID, and about a quarter of them said it significantly limited their daily activities.
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As many as two-thirds of women going through perimenopause say they have problems with memory or trouble focusing.
Getting enough rest, staying active, eating well and staying socially and mentally active may help memory during this time.
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Cancer treatments such as chemotherapy can cause trouble thinking, concentrating or remembering. Some people notice small changes, while others have bigger problems.
These problems may start during or after treatment. Ask your care team when they might start and how long they might last.
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Brain fog is linked with autoimmune and long-term conditions like lupus, multiple sclerosis and fibromyalgia. It can also follow a long hospital stay.
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Hormone changes, such as during pregnancy or menopause, are a known cause of brain fog.
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Cleveland Clinic lists neurodivergent conditions like ADHD and autism among possible causes of brain fog.
Mood, anxiety & a foggy mind
Depression and anxiety can cloud thinking.
Mental health conditions like anxiety and depression are common causes of brain fog.
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NIMH lists trouble concentrating, remembering or making decisions among the signs of depression, along with low energy and feeling slowed down.
Sometimes people notice the fog before they notice the low mood.
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Anxiety is a known cause of brain fog.
When your mind is busy scanning for danger or replaying worries, it can be hard to take in new information or remember where you put your keys.
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After a loss or a very stressful event, many people find it hard to concentrate or remember things. Be gentle with yourself while your mind and body adjust.
Brain fog or something more?
Everyday forgetfulness vs. signs to get checked.
Many people with brain fog worry that it could be the start of dementia. Most of the time, forgetfulness has other causes. But some changes are worth checking with a doctor.
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- Forgetting names or appointments, but remembering later
- Losing track of the day of the week, then figuring it out
- Misplacing things now and then and retracing your steps
- Sometimes struggling to find the right word
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- Getting confused about time or place
- Having trouble with familiar tasks
- Losing things and being unable to retrace your steps
- Memory loss that disrupts daily life
- New, ongoing problems with words when speaking or writing
These can have many causes, and some are treatable. A doctor can help work out what’s going on.
Working around the fog
Practical tools for foggy days.
While you look for the cause, simple tools can take pressure off your memory and focus.
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Writing down important information helps with brain fog.
- Keep important names and phone numbers in one easy-to-find place
- Keep a handy list of key information
- Use a planner or phone to track appointments and tasks
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Schedule the tasks that need the most focus for the times of day you feel sharpest. Keeping a daily routine also helps.
If you nap, keep daytime naps under an hour so they don’t disturb your night sleep.
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Taking short breaks during the day can help clear the fog.
- Step outside for fresh air
- Stretch or walk around
- Look away from screens
- Have a glass of water
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- Close extra tabs and apps
- Finish one task before starting the next
- Break big jobs into small steps
- Turn off notifications while you focus
Habits that help clear the air
Sleep, movement, food and a curious mind.
There’s no single treatment for brain fog, but everyday habits support a clearer mind, whatever the cause.
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Improving sleep habits is one of the first steps for brain fog. Adults need at least 7 hours a night.
- Keep regular sleep and wake times
- Make your bedroom dark, cool and quiet
- Put screens away before bed
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Getting about 30 minutes of physical activity a day can help with brain fog.
If you live with long COVID or a condition where effort makes symptoms worse, talk with your clinical provider about pacing before increasing activity.
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Eating healthy, nutritious meals supports your brain’s energy.
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Staying socially active, like joining a club, and mentally active, like doing puzzles or learning a new skill, may help memory and focus.
Puzzles, games and mind-body practices like meditation may also help some people with treatment-related fog.
Support at home and at work
Helping others understand, and asking for what helps.
Brain fog is invisible, so others may not realise how hard you’re working just to keep up. Explaining it can help people support you.
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You could say
- “My thinking is slow today. Can you send me that in a text?”
- “I’m not ignoring you. I lost my train of thought.”
- “I may need you to remind me about plans.”
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Ideas to ask about
- Fewer interruptions or a quieter workspace
- Flexible hours around your clearer times
- Short, regular breaks
- Written instructions and meeting notes
In the U.S., the Job Accommodation Network (askjan.org) gives free guidance on workplace adjustments for health conditions.
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- Give them time to find words, without finishing their sentences
- Help with reminders, gently
- Keep conversations simple and one at a time
- Notice and encourage them to see a doctor if it’s getting worse
When and where to get help
Finding the cause is the key to feeling clearer.
Talk with your doctor or clinical provider if brain fog is disrupting your daily life, for example if you often forget appointments, struggle with everyday tasks or can’t pay attention when someone is talking to you.
Things to tell your provider
- Any health conditions, recent illnesses or treatments
- Changes in sleep, mood, stress or appetite
- How long the fog has lasted, and when it’s worse
- What you’ve tried and what has helped
If low mood or anxiety are part of the picture, a counselor or therapist can help too.
📝 Worksheets for this guide
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Sources
- Cleveland Clinic. Brain Fog
- Centers for Disease Control and Prevention (CDC) (2026). Long COVID Signs and Symptoms
- Centers for Disease Control and Prevention (CDC) (2023). Long COVID and Significant Activity Limitation Among Adults, by Age — United States, June 1–13, 2022, to June 7–19, 2023 (MMWR 72(32))
- Office on Women’s Health, U.S. Department of Health and Human Services. Menopause symptoms and relief
- National Cancer Institute (NCI), NIH. Memory or Concentration Problems and Cancer Treatment
- National Heart, Lung, and Blood Institute (NHLBI), NIH. Sleep Deprivation and Deficiency: How Sleep Affects Your Health
- Centers for Disease Control and Prevention (CDC) (2024). FastStats: Sleep in Adults
- National Institute of Mental Health (NIMH). Depression (brochure)
- Alzheimer’s Association. 10 Early Signs and Symptoms of Alzheimer’s and Dementia
- U.S. Equal Employment Opportunity Commission (EEOC). Other Federal Resources on the Employment of People with Disabilities (Job Accommodation Network)
- 988 Suicide & Crisis Lifeline (SAMHSA). 988 Suicide & Crisis Lifeline
- Find A Helpline (ThroughLine). Find A Helpline
This guide is for education and self-care. It is not a diagnosis or a substitute for professional care. Please talk to a counselor or clinical provider about your health. Reviewed October 2026.
