FEEL WELL • BRAIN FOG

Brain fog:
what is actually happening?

LAST REVIEWED: 2026-10-24 • By the LatelyWell editorial team • How we write & review

Losing words, walking into rooms and forgetting why, struggling to concentrate in meetings. Memory and concentration changes are common around menopause, and for most women they are temporary. Here is what the research says, what helps, and when to get checked.

What women mean by "brain fog"

"Brain fog" is not a medical diagnosis, but most women recognise it immediately. It can include:

• Forgetting words, names or why you walked into a room.
• Losing your train of thought mid-sentence.
• Finding it harder to concentrate or to juggle several tasks at once.
• Feeling mentally slower or more easily overwhelmed.
• Misplacing things more often.

The NHS lists problems with memory and concentration among the common symptoms of perimenopause and menopause. For many women these changes are more frightening than physical symptoms, partly because of worry about dementia. The reassuring news is that the research points to a different picture.

What the research says

The best long-term evidence comes from large studies that followed women through the menopause transition. The Study of Women's Health Across the Nation (SWAN), a large US study, found that during perimenopause some women did not show the usual improvement on repeated memory and processing-speed tests that comes from practice, and that performance returned to expected levels after menopause. In other words, the changes were measurable but modest and, for most women, temporary.

The British Menopause Society has published guidance to help clinicians tell menopause-related brain fog apart from early dementia. Dementia before 65 is uncommon, and menopausal memory symptoms usually fluctuate alongside other symptoms such as poor sleep and hot flashes, whereas dementia typically involves progressive decline that affects everyday function.

Why it happens

Researchers think several things combine:

• Oestrogen and the brain. Oestrogen acts on brain areas involved in memory and attention. Large fluctuations in perimenopause may temporarily affect how efficiently these systems work.
• Poor sleep. Broken sleep has a direct and well-known effect on memory, attention and mood. If night sweats or insomnia are waking you, this alone can explain a lot. See why you might be waking at 3am.
• Hot flashes. Some studies have linked frequent hot flashes with poorer memory performance.
• Mood and stress. Anxiety and low mood use up mental bandwidth, and both are more common in perimenopause. Midlife can also be one of the busiest, most demanding periods of life.

Other causes worth ruling out

Because brain fog is a description rather than a diagnosis, it is worth considering other common, treatable causes, especially if your symptoms are severe or do not fit the usual pattern:

• Iron deficiency anaemia, which can follow heavy periods in perimenopause.
• Thyroid problems, which are more common in women in midlife.
• Low vitamin B12, particularly if you follow a vegan diet or take certain medicines such as metformin.
• Depression and anxiety.
• Sleep apnoea.
• Side effects of medicines, including some antihistamines, sleeping tablets and pain relief.
• Alcohol use.

A GP can arrange simple blood tests if needed. Mention any other symptoms such as fatigue, feeling cold, hair changes, breathlessness or heavy periods.

What helps

Improve sleep first

If sleep is poor, it is usually the most powerful lever. Treating night sweats and using CBT for insomnia techniques can help. NICE recommends CBT for menopause-related sleep problems and low mood.

Talk about treatment

HRT can help with symptoms such as hot flashes, night sweats and sleep disturbance, which in turn may help concentration. The evidence on whether HRT directly improves memory is mixed. NICE notes that HRT should not be started purely to prevent dementia, as the evidence does not support that. The Menopause Society's position is similar. Whether HRT is right for you depends on your overall symptoms and health, so discuss it with a clinician.

Look after brain health basics

The things that support brain health in general also support it now:

• Regular physical activity, including aerobic exercise and strength training, is linked with better cognitive health.
• Social connection and mentally engaging activities, such as learning something new.
• Managing blood pressure, blood sugar and cholesterol, which matter for long-term brain health.
• Limiting alcohol and not smoking.
• Treating hearing loss if you have it. Hearing loss in midlife is recognised as a risk factor for later dementia.

Practical workarounds

While symptoms last, reduce the load on your working memory:

• Write things down. Use one notebook or one app rather than scraps of paper.
• Use calendar reminders for appointments and tasks.
• Give important items, such as keys and glasses, a fixed home.
• Do one thing at a time where you can, especially tasks that need concentration.
• Schedule demanding work for the time of day when you feel sharpest.
• Tell people. Many women find it helps to say "I've lost the word, give me a second" rather than trying to hide it.

At work

If memory or concentration problems are affecting your job, you are not alone, and support may be available. In the UK, workplace menopause guidance from ACAS and the Chartered Institute of Personnel and Development (CIPD) suggests reasonable adjustments such as written instructions, flexible working, or quieter workspaces. Similar guidance exists in Australia and in many US workplaces. You do not have to share every detail with your employer, but a conversation with your manager or occupational health may help.

A simple two-week experiment

If brain fog is bothering you, it can help to gather some information before your appointment and to test what makes a difference for you. For two weeks, try this:

• Each evening, rate your focus from 1 to 5 and note one example of a lapse, if there was one.
• Record your sleep the night before: roughly how long, and how many times you woke.
• Note hot flashes, mood and stress on the same day.
• Note alcohol and caffeine.
• Pick one change to try in the second week, such as a fixed wake-up time, a daily walk in daylight or no alcohol on weekdays.

At the end, look for patterns. Many women find that their worst days follow their worst nights. That is useful to know, because it points towards sleep and night sweats as the first things to treat. If there is no clear pattern, or the lapses are getting more frequent, that is useful information for your doctor too.

How family and colleagues can help

Brain fog can knock confidence, especially for women who are used to being the organised one at home or at work. It can help to explain to the people around you what you are experiencing, that it is common and usually temporary, and what helps, for example written lists rather than verbal requests, or a few extra seconds to find a word. Shared calendars and household to-do lists also spread the mental load.

When to see a doctor

Make an appointment if:

• Memory or concentration problems are affecting work, relationships or daily life.
• Symptoms are getting steadily worse rather than fluctuating.
• Other people are noticing significant changes, such as getting lost in familiar places, repeating questions often, or struggling with everyday tasks you used to manage easily.
• You have other symptoms such as low mood, extreme tiredness, weight change or heavy periods.
• You are under 45 and have other menopause-type symptoms.

Before you go, write down specific examples: what happened, when, how often, and how it affected you. Note other symptoms too, especially sleep, mood and hot flashes. Our appointment preparation guide can help you organise these notes.

Frequently asked questions

Does brain fog mean I'm getting dementia?

For most women, no. Research such as the SWAN study suggests that memory and concentration changes around menopause are usually modest and temporary. Dementia before 65 is uncommon. If problems are steadily worsening or affecting daily life, ask for an assessment.

Where to find reliable information

If you want to read further, these organisations publish free, evidence-based information for the public:

• UK: the NHS menopause pages, the NICE menopause guideline and the Women's Health Concern factsheets from the British Menopause Society.
• US: The Menopause Society, ACOG and the National Institute on Aging.
• Australia: Jean Hailes for Women's Health and the Australasian Menopause Society.

Guidance differs a little between countries, and treatment names and availability vary, so check what applies where you live and talk to a clinician about your own situation.

The bottom line

Brain fog around menopause is real, common and, for most women, temporary. It is usually tangled up with poor sleep, hot flashes, stress and mood, which means there is plenty that can be done. Ruling out other causes such as low iron or thyroid problems, improving sleep and discussing treatment for other symptoms can all make a difference. If your symptoms are worsening or affecting everyday life, ask for an assessment rather than worrying alone.

Educational information only; not medical advice, diagnosis or treatment. Seek professional care for symptoms that are severe, persistent, worsening or concerning.