Identifying and managing primary hypertension (high blood pressure) in adults aged 18 years and older, including those with type 2 diabetes, is crucial for preventing cardiovascular diseases. This guideline aims to provide healthcare professionals with updated criteria for diagnosing hypertension accurately and effectively, ultimately reducing the risk of heart attacks and strokes.
Measuring Blood Pressure: Ensuring Accuracy
Accurate blood pressure measurement is the cornerstone of hypertension diagnosis. Healthcare professionals must receive proper training and undergo regular performance reviews to maintain proficiency in blood pressure measurement techniques.
When using automated devices, it is essential to palpate the radial or brachial pulse first. Irregularities may necessitate manual measurement using direct auscultation over the brachial artery to ensure accuracy. Devices used for blood pressure measurement should be validated, maintained, and recalibrated according to the manufacturer’s guidelines. For validated devices, refer to the British and Irish Hypertension Society’s website.
Measurements in clinical and home settings should be standardized. The environment should be relaxed and temperate, with the individual seated quietly, arm supported and outstretched, and using a cuff size appropriate for their arm.
Addressing Postural Hypotension
For individuals experiencing symptoms of postural hypotension, such as falls or dizziness, blood pressure should be measured in both lying and standing positions.
Initially, measure blood pressure with the person lying down (or seated if lying down is not feasible). Repeat the measurement after they have been standing for at least one minute. A systolic blood pressure decrease of 20 mmHg or more, or a diastolic blood pressure decrease of 10 mmHg or more after standing, indicates postural hypotension.
If postural hypotension is confirmed, identify and address potential causes, including medication review. Manage appropriately and consider falls prevention strategies. Subsequent blood pressure measurements should be taken in a standing position. If symptoms persist despite addressing likely causes, specialist referral should be considered.
In cases where symptoms suggest postural hypotension but initial seated measurements were taken, and the blood pressure drop is below the thresholds, repeat measurements starting from a lying position to ensure accurate assessment. If measurements do not confirm postural hypotension despite suggestive symptoms, consider specialist referral for further evaluation.
Hypertension Criteria for Diagnosis
To diagnose hypertension, blood pressure should be measured in both arms initially. If a difference of more than 15 mmHg is observed, repeat the measurement. If the difference persists, use the arm with the higher reading for subsequent measurements.
Clinic Blood Pressure Criteria
If clinic blood pressure is 140/90 mmHg or higher, a second measurement should be taken during the same consultation. If the second reading differs significantly, a third measurement is advised. The lower of the last two measurements should be recorded as the clinic blood pressure.
For individuals with a clinic blood pressure between 140/90 mmHg and 180/120 mmHg, ambulatory blood pressure monitoring (ABPM) is recommended to confirm hypertension diagnosis. For readings of 180/120 mmHg or higher, refer to the section on specialist referral. If ABPM is unsuitable or not tolerated, home blood pressure monitoring (HBPM) should be offered as an alternative.
Alt Text: Clinic blood pressure targets for hypertension management in adults under 80 years old, categorized by condition including primary hypertension, type 1 diabetes, and chronic kidney disease severity.
Ambulatory and Home Blood Pressure Monitoring Criteria
When using ABPM to confirm hypertension, ensure at least two readings per hour during waking hours (e.g., 8:00 AM to 10:00 PM). Diagnosis is confirmed using the average of at least 14 measurements taken during usual waking hours.
For HBPM, for each recording, take two consecutive measurements one minute apart while seated. Blood pressure should be recorded twice daily, ideally morning and evening, for 4 to 7 days. Discard the first day’s readings and use the average of the remaining measurements to confirm diagnosis.
Hypertension diagnosis is confirmed with a clinic blood pressure of 140/90 mmHg or higher AND an ABPM daytime average or HBPM average of 135/85 mmHg or higher.
If hypertension is not diagnosed but target organ damage is present, investigate for alternative causes. If hypertension is not diagnosed, clinic blood pressure should be measured at least every 5 years, and more frequently if readings are near 140/90 mmHg.
Annual Blood Pressure Measurement for Type 2 Diabetes
Adults with type 2 diabetes without prior hypertension or renal disease should have their blood pressure measured at least annually. Lifestyle advice should be offered and reinforced proactively.
Investigating Secondary Causes
Consider specialist investigations for individuals with signs or symptoms suggesting secondary hypertension.
Assessing Cardiovascular Risk and Target Organ Damage
Formal cardiovascular risk estimation is vital for discussing prognosis and treatment options for hypertension, considering both blood pressure levels and other modifiable risk factors. Cardiovascular risk should be estimated based on NICE guidelines for cardiovascular disease, using clinic blood pressure measurements.
For all individuals with hypertension, offer the following assessments: urine test for protein (albumin:creatinine ratio) and hematuria, blood sample for HbA1c, electrolytes, creatinine, eGFR, total and HDL cholesterol, fundoscopy for hypertensive retinopathy, and a 12-lead ECG.
Treating and Monitoring Hypertension
Lifestyle interventions are crucial for managing hypertension. Offer lifestyle advice to individuals with suspected or diagnosed hypertension, and continue to reinforce this advice. Enquire about diet and exercise habits, providing guidance and materials to promote healthy changes. Assess alcohol consumption and advise reduction if excessive. Discourage high intake of coffee and caffeine. Recommend low dietary sodium intake through reduced or substituted salt, with caution on potassium-based substitutes for specific populations. Calcium, magnesium, or potassium supplements are not recommended for blood pressure reduction. Offer smoking cessation advice and support. Inform individuals about local support initiatives for lifestyle changes.
Alt Text: Recommended clinic blood pressure targets for managing hypertension in adults aged 80 years and older, considering conditions like primary hypertension, type 1 diabetes, and chronic kidney disease.
Initiating Antihypertensive Drug Treatment
Antihypertensive drug treatment, alongside lifestyle advice, should be offered to adults of any age with persistent stage 2 hypertension. Clinical judgment is essential for frail or multimorbid individuals.
Discuss drug treatment with adults under 80 with persistent stage 1 hypertension and target organ damage, established cardiovascular disease, renal disease, diabetes, or a 10-year cardiovascular risk of 10% or higher. Consider treatment for those under 60 with stage 1 hypertension and less than 10% risk, recognizing lifetime risk may be underestimated. For those over 80 with stage 1 hypertension and clinic readings over 150/90 mmHg, consider drug treatment. Specialist evaluation for secondary causes and detailed risk-benefit assessment are advised for adults under 40 with hypertension.
Monitoring Treatment and Blood Pressure Targets
Use clinic blood pressure to monitor response to lifestyle changes or drug treatment. Check for postural hypotension in those with type 2 diabetes, postural hypotension symptoms, or aged 80 and over. Treat to standing blood pressure targets if postural hypotension is present. Advise home blood pressure monitoring (HBPM) for self-monitoring. Consider ABPM or HBPM for white-coat or masked hypertension. Provide training for HBPM users.
For adults under 80, aim for clinic blood pressure below 140/90 mmHg. For those 80 and over, target below 150/90 mmHg, using clinical judgment for frailty or multimorbidity. When using ABPM or HBPM for monitoring, waking hours average targets are below 135/85 mmHg for under 80s and below 145/85 mmHg for over 80s. Maintain these levels consistently. Use the same blood pressure targets for individuals with and without cardiovascular disease. Annual care reviews are necessary to monitor blood pressure, provide support, and discuss lifestyle, symptoms, and medication.
Choosing Antihypertensive Drug Treatment
For drug treatment choices in chronic kidney disease, refer to NICE guidelines on chronic kidney disease. Once-daily dosing is preferred when possible. Prescribe non-proprietary drugs when suitable to minimize costs. Treat isolated systolic hypertension (≥160 mmHg systolic) similarly to combined hypertension. Manage hypertension in women of childbearing potential, pregnancy, or breastfeeding according to NICE guidelines on hypertension in pregnancy.
For adults of Black African or African-Caribbean origin, consider angiotensin II receptor blockers (ARBs) over ACE inhibitors. For those with cardiovascular disease, follow disease-specific NICE guidelines first, then manage uncontrolled blood pressure according to these hypertension guidelines.
Step 1 treatment typically involves an ACE inhibitor or ARB for most adults under 55 and those with type 2 diabetes of any age. Offer ARB if ACE inhibitors are not tolerated. Do not combine ACE inhibitors and ARBs. For those 55 or older without type 2 diabetes, or of Black African or African-Caribbean origin without type 2 diabetes at any age, offer a calcium-channel blocker (CCB). If CCBs are not tolerated, offer thiazide-like diuretics. For heart failure, use thiazide-like diuretics and follow NICE guidelines on chronic heart failure. Thiazide-like diuretics such as indapamide are preferred over conventional thiazides like bendroflumethiazide or hydrochlorothiazide. For individuals stable on bendroflumethiazide or hydrochlorothiazide, continue current treatment.
Step 2 treatment involves adding a CCB or thiazide-like diuretic if hypertension is uncontrolled on an ACE inhibitor or ARB, or adding an ACE inhibitor, ARB, or thiazide-like diuretic if uncontrolled on a CCB. For Black African or African-Caribbean individuals without type 2 diabetes uncontrolled on step 1, consider ARB over ACE inhibitor at step 2. Step 3 treatment involves a combination of ACE inhibitor or ARB, CCB, and thiazide-like diuretic if step 2 is insufficient.
Step 4 treatment for resistant hypertension (uncontrolled on optimal doses of three drugs) requires confirmation of elevated clinic readings with ABPM or HBPM, postural hypotension assessment, and adherence discussion. Consider adding spironolactone for potassium levels ≤4.5 mmol/l, monitoring sodium, potassium, and renal function within one month and regularly thereafter. For potassium >4.5 mmol/l, consider alpha- or beta-blockers. Seek specialist advice if blood pressure remains uncontrolled on four drugs.
Criteria for Same-Day Specialist Referral
Refer for same-day specialist assessment if clinic blood pressure is 180/120 mmHg or higher with retinal hemorrhage or papilledema (accelerated hypertension), life-threatening symptoms (new confusion, chest pain, heart failure signs, acute kidney injury), or suspected pheochromocytoma (labile/postural hypotension, headache, palpitations, pallor, abdominal pain, diaphoresis).
For severe hypertension (≥180/120 mmHg) without immediate referral signs, investigate for target organ damage promptly. If damage is found, consider immediate drug treatment. If not, repeat clinic blood pressure within 7 days or consider ABPM/HBPM with clinical review within 7 days to confirm diagnosis.
Conclusion
Adhering to these Hypertension Criteria For Diagnosis and management is essential for healthcare professionals to accurately identify and treat hypertension. By implementing these guidelines, clinicians can significantly contribute to reducing cardiovascular risks and improving patient outcomes. This comprehensive approach, from precise measurement techniques to tailored treatment strategies and clear referral criteria, ensures optimal care for individuals with or at risk of hypertension.
