Everything you need to know about brain fog

Once you know what’s causing your mental wooziness, you can take action to start thinking straight again. 

We all have the odd off-day when we don’t think as clearly as we should, but when forgetfulness, trouble focusing or making decisions, and feeling mentally sluggish become the norm, then there might be something behind it worth investigating.

Menopause is a time of hormonal change when a drop in oestrogen levels is often to blame for sub-optimal brain power. Poor quality sleep, which also happens more at menopause, is another culprit, while sleeping too much can also make you feel befuddled.

Take a look at other aspects of your lifestyle too. Do you drink enough water? Dehydration can cause mental fog. Is your diet lacking in vitamin B12? This vitamin supports healthy brain function. It found in animal products, such as fish, meat, poultry, eggs and cheese, so strict vegans might be at risk of vitamin B12 deficiency.

A number of diseases can trigger brain fog. Long COVID, which can strike those who had the virus mildly as well as people who were seriously affected, often causes memory issues along with fatigue. Another post-viral condition, myalgic encephalomyelitis (ME), also known as chronic fatigue syndrome, is similarly characterised by problems with thinking, memory and concentration. An underactive thyroid can sometimes be to blame, as can depression and stress.

Some medications affect cognitive function, and “chemo” brain is a common phenomenon after cancer treatment.

A regular sleep pattern, healthy diet and exercise are likely to help. But don’t exercise too vigorously if there’s a chance you might have a post-viral problem, when sufferers are usually advised to pace themselves. Exercises for your brain, such as word puzzles, on the other hand, might be beneficial. Aim to manage your stress—but not with alcohol. 

See your GP if you’re worried and describe any other symptoms you have. They might order tests to get to the bottom of your brain fog. Mention any medications you think might be causing the problem.