Impairments of memory, concentration and thinking are often described as ‘brain fog’ and this can be common during the perimenopause and menopause. For some women, a change in cognitive abilities is unsettling and may lead to worries about the possibility of dementia or other conditions relating to the brain.
Although brain fog can be debilitating at times, there are effective treatments for it, such as HRT, and measures you can take to improve it and reduce the impact it has on your life.
It is also important to be aware of your brain health with regards to the future, and this booklet includes ways to reduce the risk of developing dementia in later life.
What is brain fog?
Brain fog is a descriptive term for a collection of symptoms affecting your thinking skills. It includes memory problems, difficulty recalling words, names, stories or numbers, a lack of mental clarity, difficulty focussing, distractibility, forgetting intentions (why did I come into this room?), word-finding problems and sluggish or fuzzy thinking.
In general, brain fog can be caused by a lack of sleep, stress, a poor diet, as a side effect of medication (such as chemotherapy) or due to a medical condition such as anaemia, an underactive thyroid gland, depression, chronic fatigue syndrome, or migraine for example.
Brain fog is also common when there are hormonal changes such as during pregnancy (sometimes referred to as ‘baby brain’), and during the perimenopause and menopause.
How hormones help your brain
The brain is full of estrogen receptors in areas of learning and areas that regulate emotion. Estrogen stimulates the brain and keeps your neurons firing; it also works as a potent anti-inflammatory agent.
Testosterone (produced by the ovaries too) strengthens the nerves in the brain and the arteries that supply the brain with blood flow, which is vital to protect against dementia. It is thought that testosterone also helps with mental energy, drive and motivation.
Impact of declining hormones on the brain
Changes in the brain during the perimenopause and menopause can lead to a narrowing of the temperature control zone in the hypothalamus. This can lead to hot flushes and night sweats. Hot flushes are shown to cause memory problems in women and night sweats cause disturbed sleep which can lead to reduced verbal learning and memory.
You may notice changes to your memory, your ability to stay focussed and follow instructions or conversations, or to work through complex problems and decisions quickly and efficiently.
Brain fog is one of the main reasons women struggle with symptoms in the workplace, where cognitive demands are often at their highest.
The mental load of professional, domestic and caring responsibilities can become overwhelming and bring about regret and frustration at things being forgotten or neglected. This can lead to further negative thoughts and perhaps feelings of guilt and shame.
The term ‘brain fog’ doesn’t fully encapsulate the knock-on effects it can have to a woman’s confidence or reflect the impact it can have on those close to her.
You may also experience other psychological symptoms during perimenopause or menopause such as anxiety, low mood or irritability. You can read more about these other symptoms here.
Ways to help brain fog
If you are suffering with brain fog, it is important to have treatment to relieve any hot flushes and night sweats, and to restore your sleep. Topping up your hormones by using HRT is the most effective treatment for these symptoms.
As well as HRT there are several other things you can do to help brain fog:
- Undertake regular aerobic exercise (it doesn’t have to be too intense, a brisk daily walk is good). Aim for 150 minutes per week.
- Stop smoking
- Make sure that you have your blood pressure checked and that this is kept within a normal range
- Eat a healthy diet with plenty of fruits and vegetables, protein and healthy fats; a Mediterranean diet is a good place to start
- Try and get plenty of sleep
- Stay socially connected with friends and loved ones
- Pursue activities you enjoy and make time for relaxation
- Use aids to support your memory and mental load, including to-do lists, calendar reminders, alerts on your phone, post-it notes in strategic places, whatever works for you!
Future brain health
Women are more at risk of developing dementia after the menopause and this is not simply because they live longer than men. Studies show that women’s brain cells die at a faster rate than men’s. This is thought to be related to sex hormones but the exact reasons are not clear.
Dementia is not caused by age alone but by disease processes in the brain. The known risk factors for developing dementia include some factors you can’t control such as your age, genetics and ethnicity, but also some factors you can influence such as your cognitive reserve – this relates to your level of education, job complexity and social isolation – and how healthy your lifestyle is.
Some medical conditions increase your risk of developing dementia such as obesity, cardiovascular disease (including high blood pressure, raised cholesterol and type 2 diabetes), hearing loss, traumatic brain injury and depression.
As with any system of the body, it is good to know how to look after your brain and do what you can to keep it healthy for as long as possible.
Reduce your risk of dementia
Keep your mental skills sharp:
Make sure you still challenge your thinking skills on a regular basis. Reading, playing games, doing puzzles, learning a new hobby, language or a musical instrument are great ways to do this.
Prioritise sleep:
Protect your sleep and try and get a minimum of 7 hours a night as a general rule. The deep sleep part of the sleep cycle is thought to be the most beneficial to your brain health. Read more tips to improve sleep here.
Look after your mental wellbeing:
This includes reducing stress, taking time to relax and unwind, getting help for anxiety or depression when needed, and undertaking activities purely for pleasure.
Stay connected:
Maintaining close relationships is vital to reduce social isolation. Regular time spent in person with those close to you positively improves mental wellbeing and reduces your risk of dementia in the future.
Get help for hearing difficulties:
If you or others think your hearing maybe affected, seek help for it. Individuals with hearing loss are at a greater risk of dementia, possibly due to the increased social isolation that hearing loss can cause.
Look after your heart and blood vessels:
Your brain needs a good supply of healthy blood to function well. Keep your cardiovascular system healthy by cutting out smoking, reducing alcohol, treating high blood pressure and cholesterol, being physically active for an average of 2.5 hours a week, and staying a healthy weight.
Feed your brain:
A healthy diet of predominantly plant-based foods, healthy fats, and gut-friendly bacteria is good for your brain health. Read our Eating Well booklet for more information.
Does taking HRT reduce your risk of dementia?
Although the evidence is mixed, some recent studies have shown that taking HRT can reduce your risk of developing Alzheimer’s and other neurological diseases, and there is some consensus that estrogen is protective against the formation of plaques in the brain. Body identical HRT within 6 years of menopause is thought to be most protective and HRT should always be taken in combination with the healthy lifestyle factors described above. At present HRT cannot be recommended for the sole purpose of preventing cognitive decline or dementia as further research is needed.
More information on brain fog and memory difficulties from the International Menopause Society
Last updated: June 2026
