Arterial Hypertension: The Right Numbers, the Right First Drugs and Why Two Often Beat One
High blood pressure is called silent because it produces no sensation, and that is the whole clinical problem: there is nothing to feel, nothing to prompt action, and the damage accumulates in the artery wall, the heart muscle and the kidney over decades rather than weeks.
The number that makes it worth taking seriously: every 10 mmHg reduction in systolic pressure is associated with roughly a fifth fewer major cardiovascular events and about a quarter fewer strokes. That is a large return for a tablet taken in the morning, and it is why the target matters more than how you feel.
📊 The categories, and the target the categories do not give you
| Category | Systolic | Diastolic | What follows |
|---|---|---|---|
| Normal | Below 120 | Below 80 | Nothing, recheck periodically |
| Elevated | 120 to 129 | Below 80 | Lifestyle measures, recheck in three to six months |
| Stage 1 | 130 to 139 | 80 to 89 | Lifestyle; medication if cardiovascular risk is high, or if there is diabetes, kidney disease or existing heart disease |
| Stage 2 | 140 or above | 90 or above | Medication plus lifestyle, usually two drugs from the start |
And the part that is usually missing: the treatment target for most adults is below 130/80. In people over about 80, or who are frail, or who become dizzy on standing, a less tight target is deliberately chosen, because the harm from falls outweighs the benefit of the last few millimetres. Knowing your own agreed target is worth more than knowing your last reading.
🏠 Home readings use a different number, and that matters
Blood pressure measured at home or over 24 hours predicts outcomes better than clinic readings, and the thresholds are lower because the clinic environment pushes the figure up.
- 🏥 Clinic: hypertension from 140/90 by traditional criteria, from 130/80 by the categories above
- 🏠 Home average: hypertension from 135/85
- 🕒 24-hour monitor, daytime average: from 135/85; whole 24-hour average from 130/80
That gap produces two situations with opposite implications, and neither can be detected without measuring in both places.
💡 White-coat hypertension is high in the clinic and normal at home. It carries lower risk than sustained hypertension, and treating it on clinic readings alone leads to over-medication, dizziness and falls.
Masked hypertension is the reverse — normal in the clinic, high at home — and it is the dangerous one, because it carries close to the same risk as sustained hypertension while being reassured about at every appointment. It is commoner in men, smokers, people with diabetes, and those under work stress. The only way to find it is to measure outside the clinic.
🩺 How to measure so the number means something
- 🪑 Sit with back supported and feet flat, arm resting at heart level, for five minutes of quiet first
- ☕ No caffeine, smoking or exercise for 30 minutes beforehand, and empty your bladder
- 📐 Correct cuff size, on bare skin, mid-upper arm. A cuff too small reads falsely high, and this is the commonest measurement error
- 🤐 Do not talk during the reading, which adds several millimetres
- 🔢 Two readings a minute apart, morning and evening, for seven days, then discard day one and average the rest. That average is the number treatment decisions should be made on
- 📉 Use an upper-arm monitor, not a wrist device
Single readings are close to meaningless. Blood pressure varies by 20 mmHg or more through a normal day, and chasing individual spikes is how people end up over-treated and anxious.
🔍 When it is not simply essential hypertension
About nine in ten cases have no single identifiable cause. The remaining one in ten matters out of proportion, because treating the cause can resolve the pressure.
| Cause | When to think of it |
|---|---|
| Obstructive sleep apnea | The commonest identifiable cause. Snoring, witnessed breathing pauses, daytime sleepiness, night-time urination. Worth screening in anyone whose pressure will not come down — see our guide to obstructive sleep apnea |
| Primary aldosteronism | Substantially commoner than once believed, perhaps one in five of those with resistant hypertension, and potentially curable where one adrenal gland is responsible. Low potassium is a clue and is frequently absent. Screened with an aldosterone-to-renin ratio, and badly under-tested |
| Kidney disease, or narrowed renal arteries | Protein or blood in the urine, reduced eGFR, or pressure that jumps sharply after starting an ACE inhibitor |
| Thyroid disease | Both over and underactive raise pressure, and both are treatable |
| Phaeochromocytoma | Rare. Episodic pressure surges with headache, sweating and palpitations occurring together |
| Coarctation of the aorta | Younger patients, with a clear difference in pressure between arms or weak leg pulses |
💊 Medicines and substances that raise blood pressure
Worth reviewing before adding a drug, because removing one is simpler than countering it.
- 💊 Anti-inflammatory painkillers — ibuprofen, diclofenac, naproxen. The commonest culprit by far, and they also blunt the effect of the tablets already being taken
- 👃 Decongestants containing pseudoephedrine, including in cold remedies
- 💊 Combined hormonal contraceptives, and some hormone therapies
- 💭 Steroid tablets, and ciclosporin or tacrolimus
- 🧠 Venlafaxine at higher doses, and some ADHD medicines
- 🍭 Liquorice in quantity, which genuinely does this
- 🚫 Cocaine and amphetamines, and heavy alcohol
- 💧 Some herbal products, particularly those containing ephedra or yohimbine
💊 The first-line classes, with names and doses
Four classes do most of the work. Thiazide-type diuretics, ACE inhibitors, angiotensin receptor blockers and calcium channel blockers. Beta blockers are no longer first-line for uncomplicated hypertension, and are used where there is another reason for them — angina, previous heart attack, heart failure, or rate control.
| Class | Example and dose | What to watch |
|---|---|---|
| Thiazide-type diuretic | Microzide (Hydrochlorothiazide) 12.5 to 25 mg once daily, in the morning. Indapamide 1.5 to 2.5 mg is the thiazide-like alternative | Sodium and potassium, uric acid and gout, glucose. More urination at first, which settles |
| ACE inhibitor | Zestril (Lisinopril) 10 mg once daily, usual range 20 to 40 mg. Ramipril and perindopril are equivalents | Kidney function and potassium at two weeks. Dry cough. Angioedema |
| Angiotensin receptor blocker | Losartan 50 mg daily up to 100 mg; telmisartan 40 to 80 mg; candesartan 8 to 32 mg | Same monitoring as above, without the cough |
| Calcium channel blocker | Adalat (Nifedipine) in modified-release form, or amlodipine 5 to 10 mg once daily | Ankle swelling, which is dose-related and the main reason people stop. Flushing, headache early on |
| Rate-slowing calcium blocker | Cardizem (Diltiazem), where rate control is also wanted | Slows the heart. Not combined with a beta blocker without specialist advice |
| Beta blocker | Lopressor (Metoprolol), where there is a separate cardiac indication | Tiredness, cold hands, slow pulse. Never stopped abruptly |
🧩 Why two drugs, and why in one tablet
Blood pressure is held up by several systems at once. Doubling the dose of one drug typically adds only a small further reduction while adding most of the side effects, whereas adding a second drug from a different class at a modest dose produces a considerably larger fall with better tolerance.
Which is why current guidance recommends starting with two drugs when the pressure is around 20/10 mmHg or more above target, rather than titrating one to its ceiling first. The usual pairings are an ACE inhibitor or ARB with either a calcium channel blocker or a thiazide.
Hyzaar (Losartan with Hydrochlorothiazide) puts an ARB and a thiazide in a single daily tablet. The argument for single-pill combinations is not pharmacological, it is behavioural: fewer tablets means better adherence, and adherence is the largest determinant of whether blood pressure is actually controlled. The trade-off is that the two doses cannot be adjusted independently, so they suit people already stable on both components or starting at standard doses.
👤 Which drug for whom
| Situation | Preferred | Avoid |
|---|---|---|
| Diabetes, or protein in the urine | ACE inhibitor or ARB — kidney protection beyond the pressure effect | — |
| Over 55, or of African or Caribbean descent | Calcium channel blocker or thiazide first; ARB preferred over ACE inhibitor if a renin-blocking drug is used | — |
| Previous heart attack, angina | Beta blocker plus ACE inhibitor | — |
| Heart failure | ACE inhibitor or ARB, beta blocker, spironolactone, SGLT2 inhibitor | Verapamil, diltiazem |
| Gout | Any of the others | Thiazides, which raise uric acid |
| Asthma | Any of the others | Non-selective beta blockers |
| Enlarged prostate with symptoms | An alpha blocker can treat both | — |
| Pregnancy, or planning it | Labetalol, modified-release nifedipine, methyldopa | ACE inhibitors, ARBs — absolutely |
⚠️ Three rules about the renin-blocking drugs.
1. The cough. ACE inhibitors cause a persistent dry tickly cough in up to one in five users, and it can begin weeks or months after starting, so the connection is often missed. It is not an allergy and it does not need the drug stopped in a panic — switching to an ARB resolves it, with cough rates no higher than placebo. Do not accept months of cough syrups for it.
2. Angioedema. Sudden swelling of the lips, tongue, face or throat on an ACE inhibitor is an airway emergency. It can occur after years of uneventful use and is more common in people of African descent. The drug is stopped permanently and never re-challenged.
3. Never an ACE inhibitor and an ARB together. The combination was tested and produced more kidney failure and more dangerous potassium elevation with no reduction in events. If you find both on your list, query it.
🤰 Pregnancy
This section exists because the consequences of getting it wrong are severe and the drugs involved are extremely common.
- 🚫 ACE inhibitors, ARBs and renin inhibitors are contraindicated in pregnancy — they damage the developing fetal kidneys and can cause fetal death. Any woman of childbearing age on one should know this and should be switched before conception, not after a positive test
- ✅ Labetalol, modified-release nifedipine and methyldopa are the options used instead. Aldomet (Methyldopa) has the longest track record in pregnancy
- 🚨 Pre-eclampsia — new high blood pressure after 20 weeks with protein in the urine, or with headache, visual disturbance, upper abdominal pain, vomiting or swelling — is an urgent situation needing same-day assessment
- 📅 Pressure that was high in pregnancy predicts hypertension later, so a check at six to twelve weeks postpartum and annually afterwards is worth asking for
🔁 When three drugs are not enough
Resistant hypertension means pressure above target despite three drugs at optimal doses, one of which is a diuretic. Before a fourth drug is added, four things get checked, and in practice most cases are explained by the first two.
- 🏠 Is it actually resistant? Confirm with home readings or a 24-hour monitor, because white-coat effect accounts for a substantial share
- 💊 Are the tablets being taken? Non-adherence is the single commonest explanation, it is nobody fault to admit, and it is far better addressed than medicated around
- 🔍 Is something raising it? The medicines and substances list above, salt intake, and alcohol
- 🧪 Screening for secondary causes, specifically sleep apnea and primary aldosteronism
Where all of that is addressed, the best-evidenced fourth drug is Aldactone (Spironolactone) 25 mg daily, which outperformed the alternatives in a dedicated trial. It needs potassium and kidney function checked within one to two weeks and periodically after, and particular care alongside an ACE inhibitor or ARB, since both raise potassium. Breast tenderness is a common reason men stop it.
The whole range is in the blood pressure category.
🧂 Lifestyle, with the millimetres attached
These get listed without figures, which makes them easy to dismiss. The figures are worth having, because several are comparable to adding a drug.
| Change | Typical systolic fall |
|---|---|
| DASH-style eating pattern — more vegetables, fruit, pulses, nuts and low-fat dairy, less red and processed meat | About 11 mmHg — the largest single non-drug effect |
| Weight loss | Roughly 1 mmHg per kilogram lost |
| Reducing salt to under 5 to 6 g a day — which means processed food, bread, sauces and eating out rather than the salt cellar | 5 to 6 mmHg |
| Aerobic exercise, 150 minutes a week of moderate activity | 5 to 8 mmHg |
| Reducing alcohol where intake is high | About 4 mmHg |
| More dietary potassium — vegetables, fruit, pulses — unless kidney disease or a potassium-raising drug | 4 to 5 mmHg |
🧂 The cheapest intervention in the field, and almost nobody mentions it. A large randomised trial of a potassium-based salt substitute, replacing ordinary table salt in cooking, found fewer strokes, fewer cardiovascular events and fewer deaths. It costs very little and requires no willpower, only a different packet.
The exception matters: not for anyone with chronic kidney disease, or taking spironolactone, an ACE inhibitor or an ARB without checking, since the added potassium can become dangerous. Worth raising at a review rather than starting blind.
🚨 Very high readings: what is an emergency and what is not
This distinction prevents both dangerous delay and unnecessary panic.
- 🔴 Hypertensive emergency — a very high reading, usually above 180/120, together with signs of organ damage: chest pain, breathlessness, weakness or speech difficulty, severe headache with visual change, confusion, or a seizure. Call emergency services. This needs controlled lowering in hospital
- 🟡 Severe reading without symptoms — above 180/120 but feeling well, with no chest pain, no neurological symptoms and no breathlessness. This needs a same-day medical review, not an ambulance. Rest quietly for ten minutes and repeat the reading first, since a single high value in a stressed person is common
- 🚫 Do not take an extra dose of your own accord, and do not use a short-acting capsule under the tongue. Dropping pressure abruptly causes strokes and heart attacks, which is the opposite of the intention
📞 When to seek help
Emergency:
- Very high pressure with chest pain, breathlessness, weakness, speech difficulty, confusion or a seizure
- Sudden swelling of lips, tongue, face or throat on an ACE inhibitor
- Sudden severe headache with visual change or vomiting
Same day:
- A reading above 180/120 that persists on repeat after ten minutes of rest
- New high pressure in pregnancy, or headache, visual change or upper abdominal pain in pregnancy
- Fainting or repeated dizziness on standing, which usually means the treatment is now too strong
Worth an appointment:
- Never having been told your target, or never having measured at home
- A persistent dry cough on an ACE inhibitor — ask about switching rather than treating the cough
- Ankle swelling on a calcium channel blocker — dose or class can be changed
- Pressure above target on three drugs — ask specifically about sleep apnea screening and an aldosterone-to-renin ratio
- Both an ACE inhibitor and an ARB on the same list
- Regular anti-inflammatory painkillers alongside blood pressure treatment
- Planning a pregnancy while on an ACE inhibitor or ARB
- No kidney function, potassium, cholesterol or urine protein check in the past year
❓ Frequently asked questions
What should my blood pressure target be?
Below 130/80 for most adults. A less tight target is chosen in people over about 80, in frailty, or where dizziness on standing occurs, because the harm from falls outweighs the last few millimetres of benefit.
Why is my home reading different from the clinic?
Because the clinic environment raises it, which is why home thresholds are lower — hypertension from 135/85 at home rather than 140/90. Home and 24-hour readings predict outcomes better than clinic ones.
What is masked hypertension?
Normal pressure in the clinic but high at home, carrying close to the same risk as sustained hypertension while being reassured about at every appointment. It is the dangerous pattern and the only way to find it is to measure outside the clinic.
How should I measure blood pressure at home?
Upper-arm monitor, correct cuff size, five minutes of quiet first, back supported and arm at heart level, no talking. Two readings a minute apart, morning and evening for seven days, then discard day one and average the rest.
Why have I been given two tablets straight away?
Because doubling one drug adds little while adding most of its side effects, whereas a second drug from a different class produces a much larger fall at modest doses. Two are recommended from the start when pressure is about 20/10 above target.
My blood pressure tablet gives me a dry cough. What now?
That is the classic ACE inhibitor cough, affecting up to one in five, and it can begin months after starting. Switching to an angiotensin receptor blocker resolves it, with cough rates no higher than placebo. It does not need cough medicine.
Why do my ankles swell on my blood pressure tablet?
Calcium channel blockers such as amlodipine and nifedipine cause dose-related ankle oedema. It is not heart failure and not fluid that a water tablet should be added for — reducing the dose or changing class is the answer.
Can I take blood pressure tablets in pregnancy?
Not ACE inhibitors or ARBs, which are contraindicated and should be changed before conception rather than after. Labetalol, modified-release nifedipine and methyldopa are the options used instead.
My pressure is high on three tablets. What should be checked?
Whether it is truly resistant on home readings, whether the tablets are being taken, whether anti-inflammatory painkillers or decongestants are involved, and screening for sleep apnea and primary aldosteronism. Then spironolactone 25 mg is the best-evidenced addition.
My reading is 185/115 and I feel fine. Should I go to hospital?
Rest quietly for ten minutes and repeat it. If it stays that high but you have no chest pain, breathlessness, weakness or visual change, this needs a same-day review rather than an ambulance. Do not take an extra dose yourself.
📑 Sources and editorial
- ACC and AHA guideline for the prevention, detection, evaluation and management of high blood pressure in adults, and ESC and ESH hypertension guidelines
- Blood Pressure Lowering Treatment Trialists Collaboration meta-analyses of event reduction per 10 mmHg systolic reduction
- Guidance on home and ambulatory blood pressure monitoring, including diagnostic thresholds and the definitions of white-coat and masked hypertension
- Evidence on initial two-drug therapy and on single-pill combinations and adherence
- Prescribing information for hydrochlorothiazide, indapamide, lisinopril, losartan, nifedipine, diltiazem, metoprolol, methyldopa and spironolactone
- The PATHWAY-2 trial of spironolactone in resistant hypertension, and the ONTARGET trial on combined ACE inhibitor and ARB therapy
- Reviews of ACE inhibitor cough and angioedema incidence and management
- Guidance on hypertension in pregnancy and on pre-eclampsia, including contraindicated drug classes
- Reviews of primary aldosteronism prevalence in resistant hypertension and of obstructive sleep apnea as a secondary cause
- The DASH dietary trials, sodium reduction meta-analyses, and the Salt Substitute and Stroke Study
- Related reading: obstructive sleep apnea, combination therapy in type 2 diabetes
- Related products: Hyzaar (Losartan + Hydrochlorothiazide), Zestril (Lisinopril), Microzide (Hydrochlorothiazide), Adalat (Nifedipine), Aldactone (Spironolactone), blood pressure category
- RXshop Editorial Team — reviewed by Robert Hayes, MD, FACC — Cardiologist & Cardiovascular Disease Specialist
Medical Disclaimer: The information in this article is for educational and informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek guidance from a qualified healthcare provider with any questions you may have regarding a medical condition, and before starting, stopping or changing any medication.