Concerns
Brain fog, memory and mood
You lose words, forget why you walked into a room and struggle to follow a meeting. Your mood swings more than it used to. Perhaps you have wondered whether it is the start of something serious, or been told it is stress.
It is one of the most frightening feelings, not recognising your own brain. Usually there are explanations that can be acted on. Many people who come to us describe it as their brain running at half speed.
Does this sound familiar?
- You lose words in the middle of a sentence.
- You read the same paragraph several times without it sinking in.
- You are more irritable or low than usual, without knowing why.
- You have been told it is stress or age.
- You are afraid it will get worse.
Why is it hard to get answers?
Brain fog is not a diagnosis, and no test measures it. So it easily becomes a question of stress or age, and often nobody takes the common causes in the body seriously.
B12, iron, the thyroid, blood sugar, sleep and hormones all affect how clearly you think. Each can look fine on its own, while several small deviations together make a difference.
With us, we look at them together, and we take you seriously when you say that something has changed.
What does the brain need to work?
The brain uses about a fifth of the body's energy. It needs steady blood sugar, oxygen carried by iron, and B12 and folate for the nerve cells to work. Thyroid hormone and oestrogen affect how quickly and clearly it works.
During sleep the brain clears away waste and stores memories. That is why a few weeks of poor sleep often show first as a poorer memory and a shorter fuse.
What could be behind it?
We often find that brain fog comes together with tiredness and poorer sleep, and that it pays to look at them together.
B12 and folate
A deficiency can cause memory problems, poor concentration and low mood, and it often develops slowly.
Read the guide: Vitamin deficiency →Iron deficiency
Low iron stores affect concentration and energy long before you become anaemic.
Read the guide: Iron deficiency →Blood sugar
Swings during the day cause dips in focus and mood, often in the afternoon.
Read the guide: Blood sugar and diabetes risk →The thyroid
A slow thyroid can make thinking sluggish and mood lower.
Read the guide: Thyroid health →The menopause
Brain fog and memory problems are common in perimenopause and usually improve with time.
Read the guide: Women's health →Sleep and stress
Poor sleep and long-term stress affect memory and concentration more than most people think.
What you can do yourself
- Eat regularly and include protein in every meal, so your blood sugar stays steady.
- Prioritise sleep, even when it feels as if you do not have time.
- Do one thing at a time. The brain copes better without constant interruptions.
- Take a walk outside every day. Movement increases blood flow to the brain.
- Write things down instead of keeping them in your head.
- Do not take B12 or other supplements at random. Measure first.
What we look at
Your symptoms and your history
How the brain fog feels, when it started, how your mood has been and what you have already tried.
Food, sleep and daily life
How regularly you eat, how you sleep, how much you move and how much you have on right now.
Tests with a purpose
We only suggest tests that could change the next step. For brain fog and low mood that often means B12, folate, homocysteine, iron status, vitamin D and the thyroid.
Tests that may be relevant
How it works
Four steps
- 01
Tell us about you
You fill in a health questionnaire about your symptoms, your sleep, what you eat and your daily life.
- 02
Take your blood test
You give a blood sample at a lab near you, in Stockholm or at any of more than 100 sampling locations across Sweden. We help you choose the tests that answer your questions.
- 03
Go through your results
You receive a personal health report and a session with one of our practitioners, and we make a plan together.
- 04
Follow up
We follow how you are getting on and adjust the plan. A new blood test after three to six months shows how your results have changed.
When to get medical help
Contact your health centre soon if you also have any of these:
- Your memory problems are getting worse quickly, or others have noticed that you have changed.
- You suddenly have difficulty speaking, finding words or moving an arm or leg. Call 112.
- You have a severe headache that is new or different from usual.
- You have felt low most of the time for more than two weeks, or have thoughts of harming yourself. Call Mind Självmordslinjen on 90101, or 112 in an emergency.
Call 112 in an emergency. Call 1177 for advice on where to get care.
Frequently asked questions
What is brain fog?
Brain fog is not a diagnosis but a way of describing thinking that feels sluggish, difficulty concentrating and a memory that lets you down. It can have many causes, from sleep and stress to a lack of B12 or iron.
Can the menopause cause brain fog?
Yes, it is common. Falling oestrogen affects memory and concentration, and poorer sleep makes it harder. For many it improves after a few years, but it is worth checking that B12, iron or the thyroid are not also contributing.
Can a vitamin deficiency affect mood?
Low levels of B12, folate and vitamin D have been linked to low mood, and a blood test shows whether you are deficient. Low mood often has several causes, and diet and supplements do not replace treatment from a doctor when it is needed.
Can food affect how clearly I think?
Yes. The brain needs regular meals, protein, fat from fish and enough B vitamins and iron. What makes a difference for you depends on your results and how you eat today.
What is included in a Health Assessment?
A health questionnaire, a personal health report and a short session with one of our practitioners. You add the blood test depending on what you want to look into, and we help you choose. If you have a long-term condition and want to find out whether your diet and lifestyle may be contributing, or you need a referral to our doctor, we also offer longer appointments.
Do I need a referral?
No. You book yourself, and the blood sample is taken at a lab near you. We have sampling locations in Stockholm and at more than 100 places across Sweden.
Would you like help finding out what is behind your brain fog? Read about the Health Assessment →
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Sources
Reviewed by
Wellth Team
Wellth
Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.
Learn more about our team →Important to know
Wellth does not diagnose or treat disease. We work with diet, lifestyle and preventive health, alongside the care you already have.
Our reports and sessions do not replace medical advice, and a test result should not be read as a diagnosis. We use both standard healthcare reference ranges and optimal ranges. A value can therefore be normal by healthcare standards and still fall outside the range associated with good health. That does not mean disease, but it can be a chance to act early.
Supplements are only recommended by a nutritional therapist as part of a consultation, never automatically from a test result.
If anything in your results needs to be looked at by a doctor, we will tell you clearly. Contact your healthcare provider if you are worried about your health. Call 1177 for advice, or 112 in an emergency.