Introduction: Why Hypertension Matters

Hypertension is not a disease in itself, but a major modifiable risk factor for cardiovascular disease (CVD). People with hypertension develop CVD, such as heart failure or angina, approximately 5 years earlier than those without. This module provides a comprehensive overview of the diagnosis, assessment, and management of hypertension in adults, based on NICE guideline NG136 (updated 2022).

Accurate Diagnosis of Hypertension

The Gold Standard: ABPM

Key Principle: Use ABPM for Diagnosis

If a clinic blood pressure (BP) reading is 140/90 mmHg or higher, diagnosis must be confirmed using Ambulatory Blood Pressure Monitoring (ABPM). This provides a 24-hour average and avoids the "white coat" effect. Home Blood Pressure Monitoring (HBPM) is the alternative if ABPM is not tolerated.

ABPM Protocol: At least 2 readings per hour during waking hours. A minimum of 14 readings are needed to calculate an average.
HBPM Protocol: Patient takes 2 readings, twice daily, for at least 4-7 days. The first day's readings are discarded, and the remaining readings are averaged.

Diagnostic Technique & Considerations

Cuff Size is Crucial: An incorrectly sized cuff can lead to significant errors. A cuff that is too small will overestimate BP, while one that is too large will underestimate it. Use the range markings on the cuff to ensure a proper fit.
Measure in Both Arms: At diagnosis, measure BP in both arms. If the difference in systolic pressure is >15 mmHg, repeat the measurement. If the difference persists, use the arm with the higher reading for all future measurements.
Night-Time Dipping: Normally, BP drops at night ('dippers'). Some people are 'non-dippers' or 'reverse dippers', which is associated with a higher CVD risk. While NICE recommends waking-hours ABPM, 24-hour monitoring provides more prognostic information by identifying these individuals.

Diagnostic Thresholds

Stage	Clinic BP (mmHg)	ABPM/HBPM Average (mmHg)
Stage 1 Hypertension	140/90 – 159/99	135/85 – 149/94
Stage 2 Hypertension	≥ 160/100	≥ 150/95
Severe Hypertension	Clinic SBP ≥ 180 or DBP ≥ 120	-

Assessment and Investigation

Initial Clinical Assessment

Once a diagnosis is confirmed, a thorough assessment is required to quantify cardiovascular risk and check for complications.

⚠️ Key Investigations for Target Organ Damage

Heart: Conduct a 12-lead ECG to look for evidence of left ventricular hypertrophy (LVH).
Kidneys: Check urine albumin:creatinine ratio (ACR) for early signs of kidney damage and dipstick for haematuria. Run bloods for urea & electrolytes (U&Es) and eGFR.
Eyes: Perform fundoscopy to check for hypertensive retinopathy (e.g., retinal haemorrhages, papilloedema).
Blood Tests: In addition to U&Es, check HbA1c (for diabetes) and a full lipid profile.
Cardiovascular Risk: Use a formal tool like QRISK3 to estimate the 10-year risk of a cardiovascular event.

Postural Hypotension

It is vital to check for postural hypotension, especially in those at higher risk, to avoid overtreatment and falls.

Who to check: Patients aged ≥80 years, patients with type 2 diabetes, or anyone reporting postural symptoms (e.g., dizziness on standing).
How to check: Measure BP while seated, then again after the patient has been standing for at least 1 minute.
Definition: A significant drop is a fall in systolic BP of ≥20 mmHg or diastolic BP of ≥10 mmHg.
Management: If present, review medications, address causes, and use the standing BP for all future treatment decisions and targets.

🚨 Urgent Referral Criteria

Same-day admission: Clinic BP ≥ 180/120 mmHg WITH signs of accelerated (malignant) hypertension (e.g., new retinal haemorrhage, papilloedema) or life-threatening symptoms (new confusion, chest pain, signs of heart failure, AKI).
Same-day admission: Suspected phaeochromocytoma (labile BP, headache, palpitations, pallor, excessive sweating).
Investigate for secondary causes: Consider for patients under 40, as 10-year risk tools may underestimate their lifetime risk and there is a higher chance of a secondary cause.

Principles of Management

Shared Decision-Making

Treatment for hypertension is about long-term risk reduction. The decision to start medication, especially for Stage 1 hypertension, is a shared one between the clinician and patient, based on their calculated cardiovascular risk and personal preferences.

NICE Framework: Offer, Discuss, Consider

NICE uses specific language to guide the strength of recommendation, reflecting the balance of benefit and risk:

OFFER (Stage 2 Hypertension): Strongest recommendation. Treatment is clearly beneficial.
DISCUSS (Stage 1 with high risk): For patients with Stage 1 hypertension plus CVD, T2DM, CKD, target organ damage, or QRISK3 ≥10%. The benefits are significant, and treatment should be strongly encouraged.
CONSIDER (Stage 1, lower risk): For patients <60y with Stage 1 hypertension and QRISK3 <10%. The 10-year risk is lower, but lifetime risk is high. Treatment is a preventative choice.
LIFESTYLE (Stage 1, lowest risk): For patients ≥60y with Stage 1 hypertension and QRISK3 <10%. Medication is not typically recommended; focus on lifestyle and annual review. For those >80y, consider drugs only if clinic BP is >150/90 mmHg.

Lifestyle Interventions: The Foundation of Care

Lifestyle advice is critical for ALL patients with hypertension, regardless of whether they take medication.

Salt Reduction: Aim for <6g per day. Reducing salt intake is highly effective. Counsel patients about hidden salt in processed foods and the high sodium content of many soluble/effervescent medications.
Weight Management: For every 1kg of weight loss, systolic BP can drop by approximately 1 mmHg.
Alcohol & Caffeine: Advise reducing excessive alcohol and caffeine intake.
Physical Activity: Encourage regular moderate-intensity exercise.
Diet: Promote a healthy, balanced diet rich in fruit and vegetables.
Smoking Cessation: Offer support and advice to stop smoking.

Pharmacological Treatment PathwayNICE NG136

The NICE treatment algorithm is based on a stepwise approach, with the initial choice determined by patient characteristics.

Step 1: First-line Treatment ("A" or "C")

If patient has Type 2 Diabetes: Offer an ACE inhibitor (ACEi) or Angiotensin Receptor Blocker (ARB). This is a compelling indication and overrides other factors.

If patient is of Black African or African-Caribbean family origin: Offer a Calcium Channel Blocker (CCB).

If patient is < 55 years old (and not in the groups above): Offer an ACEi or a low-cost ARB.

If patient is ≥ 55 years old (and not in the groups above): Offer a CCB.

Step 2: Dual Therapy ("A + C")

If BP is not controlled, offer a combination of an ACEi or ARB plus a CCB.

If a CCB is not suitable (e.g., due to oedema, intolerance, or heart failure), offer a thiazide-like diuretic (e.g., indapamide) instead.

Step 3: Triple Therapy ("A + C + D")

If BP is still not controlled, offer the combination of an ACEi or ARB, a CCB, and a thiazide-like diuretic.

Step 4: Resistant Hypertension

If BP remains uncontrolled on optimal doses of three drugs, this is resistant hypertension. Before acting, confirm adherence and re-measure BP with ABPM/HBPM. Consider adding low-dose spironolactone (if serum K+ is ≤ 4.5 mmol/L) or an alpha- or beta-blocker. Seek expert advice.

Detailed Drug Class Information

This section provides a detailed clinical summary for the main classes of antihypertensive drugs used in UK practice.

ACE Inhibitors (e.g., Ramipril, Lisinopril)

Mechanism of Action	Inhibits Angiotensin-Converting Enzyme, preventing the conversion of angiotensin I to angiotensin II (a potent vasoconstrictor). This leads to vasodilation and reduced aldosterone secretion, lowering blood pressure.
Typical Dosage Regimen	Ramipril: Start 1.25-2.5mg once daily, titrate up every 2-4 weeks to a maximum of 10mg once daily.
Adverse Effects	Dry, persistent cough (most common reason for discontinuation) Hyperkalaemia (high potassium) Postural hypotension (especially first dose) Worsening renal function Angioedema (rare but life-threatening)
Cautions	Significant renal artery stenosis (contraindicated) Pregnancy (contraindicated - teratogenic) Patients with volume depletion or pre-existing renal impairment (eGFR <60)
Monitoring Requirements	Check U&Es (urea, electrolytes, creatinine) at baseline and 1-2 weeks after initiation or any dose increase. Monitor blood pressure to assess efficacy and for hypotension.
Patient Counselling	Warn about the possibility of a dry cough and to report it if it becomes troublesome. Advise to rise slowly from sitting or lying to avoid dizziness. Explain the 'sick day rules': temporarily stop the ACEi during episodes of vomiting, diarrhoea, or feverish illness to prevent acute kidney injury. Report any swelling of the face, lips, or tongue immediately.
Practice Points	First-line for patients <55 and for all patients with Type 2 Diabetes. The cough is a class effect; switching to an ARB is the appropriate action if it occurs.
Key Drug Interactions	Potassium-sparing diuretics (e.g., spironolactone) or potassium supplements: Increased risk of severe hyperkalaemia. NSAIDs (e.g., ibuprofen): Can reduce the antihypertensive effect and increase the risk of renal damage ('triple whammy' with a diuretic). Lithium: ACE inhibitors can reduce lithium clearance, increasing the risk of toxicity. Trimethoprim (especially with co-trimoxazole): Significantly increases the risk of hyperkalaemia.

Angiotensin-II Receptor Blockers (ARBs) (e.g., Candesartan, Losartan)

Mechanism of Action	Selectively blocks the AT1 receptor, preventing angiotensin II from binding. This causes vasodilation and reduces aldosterone secretion, similar to ACE inhibitors but via a more direct mechanism.
Typical Dosage Regimen	Candesartan: Start 8mg once daily, titrate up to a maximum of 32mg once daily.
Adverse Effects	Dizziness, postural hypotension. Hyperkalaemia. Worsening renal function. Generally well-tolerated; notably, they do NOT cause a cough.
Cautions	Similar to ACE inhibitors: renal artery stenosis, pregnancy, volume depletion. Less risk of angioedema than ACE inhibitors, but caution is still required if a patient had angioedema with an ACEi.
Monitoring Requirements	Identical to ACE inhibitors: Check U&Es at baseline and 1-2 weeks after initiation or dose increase. Monitor BP.
Patient Counselling	Similar to ACE inhibitors regarding dizziness and sick day rules. Reassure patients that a cough is not expected with this medication.
Practice Points	Used as an alternative to an ACE inhibitor, primarily when a patient develops an intolerable ACEi-induced cough. Losartan has a mild uricosuric effect and can be a good choice for patients with co-existing gout.
Key Drug Interactions	Identical to ACE inhibitors (potassium-sparing diuretics, NSAIDs, lithium, trimethoprim).

Calcium Channel Blockers (CCBs) (e.g., Amlodipine, Felodipine)

Mechanism of Action	Blocks the entry of calcium into vascular smooth muscle cells, causing peripheral vasodilation and reducing blood pressure.
Typical Dosage Regimen	Amlodipine: Start 5mg once daily, titrate to 10mg once daily if required.
Adverse Effects	Ankle swelling (peripheral oedema) - very common. Flushing, headache, palpitations (due to vasodilation). Dizziness. Gingival hyperplasia (gum swelling) - rare.
Cautions	Can worsen oedema. Use with caution in patients with heart failure (though amlodipine is generally considered safe). Avoid in severe aortic stenosis.
Monitoring Requirements	Mainly clinical monitoring of blood pressure and for side effects. No routine blood tests required.
Patient Counselling	Warn about the high likelihood of ankle swelling, and that it is due to fluid shifts, not fluid retention (diuretics are often ineffective). Advise that flushing and headaches are common initially and often settle. Maintain good dental hygiene to reduce the risk of gum problems.
Practice Points	First-line for patients ≥55 or those of Black African or African-Caribbean family origin. Ankle swelling is the main limiting side effect; if it occurs, switching to an alternative class is often necessary.
Key Drug Interactions	Grapefruit juice can increase levels of some CCBs (e.g., felodipine, lercanidipine). Increased risk of myopathy when used with high-dose simvastatin (max 20mg simvastatin with amlodipine).

Thiazide-Like Diuretics (e.g., Indapamide, Chlortalidone)

Mechanism of Action	Initially reduces blood volume by inhibiting sodium reabsorption in the distal convoluted tubule. Long-term, it reduces peripheral vascular resistance.
Typical Dosage Regimen	Indapamide: 2.5mg once daily in the morning.
Adverse Effects	Electrolyte disturbances: hypokalaemia (low potassium), hyponatraemia (low sodium), hypercalcaemia (high calcium). Hyperglycaemia (may worsen glucose control). Hyperuricaemia (may precipitate gout). Postural hypotension, dizziness.
Cautions	History of gout. Significant electrolyte imbalance. Severe renal or liver impairment.
Monitoring Requirements	Check U&Es at baseline, within 4-6 weeks of starting, and annually thereafter. Also check HbA1c and uric acid if clinically indicated.
Patient Counselling	Take in the morning to avoid nocturia (passing urine at night). Warn about dizziness on standing. Report any symptoms of gout.
Practice Points	The 'D' in A+C+D. NICE prefers thiazide-LIKE diuretics (indapamide, chlortalidone) over conventional thiazides (bendroflumethiazide) due to better evidence.
Key Drug Interactions	Lithium: Diuretics reduce lithium clearance, significantly increasing the risk of toxicity. This combination should generally be avoided. NSAIDs: Can reduce the diuretic and antihypertensive effect. Drugs that prolong the QT interval: Risk is increased if diuretic-induced hypokalaemia occurs.

Management in Special Populations & Co-morbidities

Blood Pressure Targets

NICE has simplified BP targets. The target depends on age and the presence of significant kidney disease.

Patient Group	Clinic BP Target	Notes
Adults < 80 years (including T2DM)	< 140/90 mmHg	This is the standard target for most patients.
Adults ≥ 80 years	< 150/90 mmHg	A more relaxed target to reduce the risk of overtreatment and side effects like falls.
CKD with ACR ≥ 70 mg/mmol (any age)	< 130/80 mmHg	A tighter target is needed for enhanced renal protection in patients with heavy proteinuria.

Co-morbidities

The choice of antihypertensive can be influenced by co-existing conditions.

Heart Failure (HFrEF): ACEi and beta-blockers are used for their prognostic benefit in HF. CCBs are generally avoided for hypertension management in this group.
Gout: Thiazide-like diuretics can increase uric acid and should be used with caution. The ARB Losartan can be a good choice as it has a mild uricosuric effect.
Asthma: Avoid non-cardioselective beta-blockers. Cardioselective beta-blockers can be used if needed for a compelling indication like heart failure.
Pregnancy / Women of childbearing potential: ACEi/ARBs are teratogenic and must be avoided. Labetalol and Nifedipine are preferred agents. Beta-blockers can be considered first-line for women who may become pregnant.

🎯 OSCE Preparation

Counselling a Patient on Starting Treatment

Scenario: Mrs. Evans, a 56-year-old teacher, has an ABPM average of 142/90 mmHg (Stage 1 Hypertension). She does not have diabetes. Her QRISK3 score is 14%. She is anxious about starting lifelong medication.

Key Communication & Counselling Steps:

Acknowledge & Explain: "Thank you for coming in, Mrs. Evans. Your 24-hour blood pressure results show you have what we call Stage 1 hypertension. I understand it can be worrying to get a new diagnosis. It's important to know this isn't an illness, but a risk factor. It means that over time, your risk of things like a stroke or heart attack is higher than we'd like. Based on your results, that risk is about 14% over the next 10 years."
Frame the Decision (Discuss, not just Offer): "The guidelines recommend for people with your level of risk, we should discuss the pros and cons of starting a blood pressure medication. It's a long-term preventative measure, and the choice is ultimately yours. The goal is to lower that future risk."
Propose a Specific Treatment: "If you choose to start medication, because you're over 55, the best first step would be a tablet called a calcium channel blocker, most likely Amlodipine. It works by relaxing your blood vessels, which brings the pressure down."
Link to Lifestyle: "Whether or not you decide to start the tablet today, making lifestyle changes is one of the most powerful things you can do. Reducing the salt in your diet, for example, can lower blood pressure on its own. The medication works best when we also address these factors."
Action Plan & Follow-up: "What are your thoughts on starting a preventative medication? We can check your blood pressure again in a month to see how you are getting on and discuss any side effects you might have noticed, like flushing or ankle swelling which can sometimes happen."

⭐ Clinical Pharmacist Case Study

The Patient: Optimising Therapy for Resistant Hypertension

Patient Profile: Mr. Jones is a 64-year-old man with T2DM and Stage 3 CKD (eGFR 48, ACR 15 mg/mmol).
Current Medications: Ramipril 10mg OD, Amlodipine 10mg OD, Indapamide 2.5mg OD, Metformin 1g BD, Atorvastatin 80mg OD.
The Challenge: Mr. Jones's home blood pressure readings average 148/94 mmHg, despite being on optimal doses of three agents. His latest blood results show a serum potassium of 4.3 mmol/L. He reports good adherence.

Pharmacist's Consultation & Plan (SOAP Note Format)

Subjective: Patient is frustrated his BP is still not at target (<140/90 mmHg). He is worried about his kidneys. Reports good adherence and denies side effects from current medications.
Objective: BP: 148/94 mmHg (above target). Has T2DM and CKD. On optimal triple therapy (A+C+D). Serum K+ is 4.3 mmol/L.
Assessment:
1. Resistant Hypertension: BP is not at target despite optimal doses of three appropriate antihypertensive agents.
2. Candidate for Step 4 therapy: Adherence has been confirmed and his potassium level is within the safe range for initiating spironolactone (≤4.5 mmol/L).
Plan:
1. Pharmacotherapy: Recommend adding Spironolactone 25mg once daily (Step 4 therapy).
2. Counselling: Explain the rationale for adding a fourth 'water tablet' that works in a different way. Counsel on the risk of hyperkalaemia and the need for monitoring. Advise him to avoid potassium-containing salt substitutes (e.g., Lo-Salt).
3. Monitoring: Arrange for repeat U&Es (including potassium) in 1 week, and again at 1 month. This is critical due to the combined risk from Ramipril and Spironolactone, especially with pre-existing CKD.
4. Liaison: Document the plan and rationale clearly in the patient's record and communicate with the GP.

Example Consultation Dialogue

Pharmacist: "Thanks for sharing your home readings, Mr. Jones. It looks like your blood pressure is still a bit stubborn, even with the three medicines you're on. This is quite common, and we call it 'resistant hypertension'."

Patient: "So what now? I don't want to have a stroke."

Pharmacist: "Exactly. The next step in the guidelines is to add a fourth medication. Based on your recent blood test, your potassium levels are fine, so I'd recommend we add a low dose of a tablet called Spironolactone. It's another type of water tablet, but it works in a different way to the Indapamide you already take."

Patient: "Another one? Are there any problems with it?"

Pharmacist: "The main thing we need to watch is that it doesn't push your potassium level too high, especially as you're also on Ramipril. So, it's essential we get a repeat blood test done one week after you start it, and again a few weeks after that, just to make sure everything is stable. It's a very effective drug for this situation, and getting your blood pressure to target is the best thing we can do to protect your heart and kidneys long-term."

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Comprehensive Hypertension Management