In plain English
Hypertension is the most important modifiable risk factor for dementia, particularly Vascular and Mixed Alzheimer's and Vascular Dementia. Bringing blood pressure to target reduces dementia risk and slows progression. UK NICE NG136 sets out the targets and approach.
Why blood pressure matters for the brain
Chronic high blood pressure damages small blood vessels in the brain, leading to white matter disease, lacunes and chronic ischaemia. It is the leading driver of Vascular Dementia and an important contributor to mixed dementia. The 2024 Lancet Commission estimates that controlling Hypertension would prevent or delay around 7 per cent of all dementia cases worldwide.
The UK targets
NICE NG136 recommends:
- Adults under 80: clinic blood pressure below 140/90 mmHg, home blood pressure below 135/85 mmHg;
- Adults 80 and over: clinic below 150/90, home below 145/85;
- Adults with Type 2 Diabetes, kidney disease, or established cardiovascular disease: typically tighter (clinic around 130/80, home around 125/75), individualised.
How to measure accurately
A single clinic reading is a snapshot. Home monitoring or 24-hour ambulatory monitoring gives a more reliable picture. For home monitoring:
- Use a validated upper-arm device (the British and Irish Hypertension Society publishes a list);
- Sit quietly for 5 minutes first; back supported, feet flat, arm at heart level;
- Take two readings a minute apart, twice a day, for 7 days;
- Discard the first day and average the rest;
- Bring the readings to your GP.
Lifestyle measures
Several lifestyle changes reduce blood pressure meaningfully:
- Salt: reduce to under 6 g a day (around 2.4 g sodium). Most reduction comes from processed foods, not the salt shaker;
- Weight: even modest weight loss reduces blood pressure;
- Exercise: 150 minutes of moderate activity a week reduces systolic blood pressure by 4 to 9 mmHg;
- Alcohol: under 14 units a week;
- Diet: Mediterranean or DASH eating reduces blood pressure;
- Stress: structured relaxation reduces blood pressure in some people;
- Smoking: not a direct hypertensive but a major vascular risk; stopping helps.
Lifestyle changes can achieve up to 10 to 15 mmHg reduction in motivated patients with sustained adherence.
Medication
Where lifestyle alone is insufficient, NICE NG136 recommends step-wise treatment:
- First line (under 55, not of Afro-Caribbean ethnicity): ACE inhibitor (Ramipril, Lisinopril) or ARB (Losartan, Candesartan);
- First line (over 55 or Afro-Caribbean): calcium channel blocker (Amlodipine);
- Second line: combine both above;
- Third line: add thiazide diuretic (Indapamide);
- Fourth line: spironolactone, alpha-blocker or beta-blocker under specialist input.
Most medications are well tolerated and inexpensive. Side effects (dry cough with ACE inhibitors, ankle swelling with calcium channel blockers) usually have a workable alternative.
For people with dementia
Blood pressure control in people with established dementia is more nuanced. The trade-offs include:
- Reducing falls and orthostatic hypotension (avoid excessive lowering);
- Reducing further vascular events;
- Medication burden in polypharmacy;
- Quality of life and individual circumstances.
Most older adults with dementia benefit from continued blood pressure control, with regular review and attention to standing as well as sitting blood pressure.
Where to discuss
Your GP is the right starting point. Pharmacists can advise on home monitoring. Specialist Hypertension clinics exist for difficult cases.
Frequently asked questions
How often should I check my blood pressure?
Once a year as a screening check if normal. If on treatment, once a week for a fortnight every few months, or as advised by your GP.
Are home monitors reliable?
Validated upper-arm devices are. Wrist and finger devices are less reliable. The British and Irish Hypertension Society publishes a list of validated devices.
Should I take blood pressure medication for life?
Usually yes if you have established Hypertension. Some people reduce or stop medication after sustained lifestyle change with their GP's agreement.
Will medication make me feel different?
Most blood pressure medications are well tolerated. Side effects (cough, ankle swelling, fatigue) can usually be managed by switching to a different class.
What if my readings vary a lot?
Some variation is normal. The average over several days is what matters. Substantial variation may warrant 24-hour ambulatory monitoring.
References
- NICE NG136: Hypertension in adults: diagnosis and management.
- British and Irish Hypertension Society. https://bihsoc.org
- Williamson JD et al. Effect of intensive vs standard blood pressure control on probable dementia: the SPRINT-MIND trial. JAMA 2019.
- Livingston G et al. 2024 Lancet Commission on dementia prevention.