Common Causes
| Category | Examples |
|---|---|
| Sleep-related | Insomnia, sleep apnoea, shift work |
| Mental health | Depression, anxiety, ADHD, chronic stress |
| Medical | Hypothyroidism, anaemia, B12/vitamin D deficiency, diabetes (poor control) |
| Lifestyle | Excess alcohol, poor diet, dehydration, lack of exercise |
| Medication side effects | Sedating antihistamines, some antidepressants, sleep medications |
| Menopause | Common complaint during perimenopause and menopause |
Blood Tests to Consider
| Test | Purpose |
|---|---|
| FBC | Anaemia |
| TSH | Thyroid dysfunction |
| Vitamin B12 + folate | Deficiency affecting cognitive function |
| Fasting glucose/HbA1c | Diabetes affecting concentration |
| Vitamin D | Deficiency linked to fatigue and cognitive symptoms |
Practical Strategies
- Prioritise consistent sleep — 7-9 hours nightly
- Reduce multitasking — single-task focus improves output
- Take regular breaks (e.g. Pomodoro technique)
- Stay hydrated and eat regular balanced meals
- Limit alcohol, which impairs sleep quality even if it seems to help you fall asleep
- Address underlying anxiety or stress through appropriate support
Consider Adult ADHDIf poor concentration has been a lifelong pattern (not a new change) and significantly affects work, relationships, or daily function, an adult ADHD assessment may be worthwhile, as it's frequently under-diagnosed, especially in women.
Is 'brain fog' a real medical condition?
Brain fog isn't a specific diagnosis itself but is a recognised symptom in many conditions — including long COVID, chronic fatigue syndrome, menopause, depression, and thyroid disorders.
Can poor concentration be a sign of dementia?
In older adults, especially with progressive worsening affecting daily function, this should be assessed. However, in younger people or with sudden onset linked to stress/poor sleep, dementia is very unlikely to be the cause.
Does diet really affect concentration?
Yes — blood sugar fluctuations from irregular eating, dehydration, and nutrient deficiencies (iron, B12, omega-3) can measurably affect cognitive function and concentration.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.