What is the exact diagnosis protocol for Hypertension (HTN)?

Exact Diagnosis Protocol for Hypertension

Hypertension is diagnosed when blood pressure measurements of ≥140/90 mm Hg are confirmed across 2-3 separate office visits taken at 1-4 week intervals, with out-of-office confirmation strongly recommended for borderline cases. 1

Office Blood Pressure Measurement Technique

Pre-Measurement Preparation

• Patient must avoid smoking, caffeine, and exercise for 30 minutes before measurement 1, 2
• Empty bladder and sit relaxed in a quiet room with comfortable temperature for 3-5 minutes 1
• Neither patient nor staff should talk before, during, or between measurements 1, 2

Proper Positioning

• Seated with arm resting on table at heart level 1, 2
• Back supported on chair, legs uncrossed, feet flat on floor 1

Measurement Protocol

• Use validated electronic (oscillometric) upper-arm cuff device (see www.stridebp.org for validated devices) 1
• Ensure appropriate cuff size: inflatable bladder must cover 75-100% of arm circumference 1
• Take 3 measurements with 1-minute intervals between each 1, 2
• Calculate the average of the last 2 measurements 1
• If first reading is <130/85 mm Hg, no further measurement required at that visit 1, 2

Initial Evaluation Specifics

• Measure BP in both arms, preferably simultaneously 1
• If consistent difference >10 mm Hg between arms on repeated measurements, use the arm with higher BP 1
• If difference >20 mm Hg, consider further investigation for vascular pathology 1
• Measure standing BP after 1 minute and again after 3 minutes in elderly patients, diabetics, and those with symptoms of postural hypotension 1

Confirmation Strategy Based on Initial BP Level

BP <130/85 mm Hg

• Remeasure within 3 years (1 year if other cardiovascular risk factors present) 1

BP 130-159/85-99 mm Hg (High-Normal to Grade 1 Hypertension)

• Confirm with out-of-office BP measurement (home or ambulatory monitoring) due to high possibility of white coat or masked hypertension 1
• If out-of-office monitoring unavailable, require 2-3 office visits at 1-4 week intervals 1
• For borderline cases (SBP 140-160 or DBP 90-100 mm Hg), more stringent confirmation with measurements on 4-5 separate occasions is recommended 1, 2

BP ≥160/100 mm Hg (Grade 2 Hypertension)

• Confirm within a few days or weeks 1
• May diagnose on single visit if BP ≥180/110 mm Hg AND evidence of cardiovascular disease is present 1, 2

Out-of-Office Blood Pressure Confirmation

Out-of-office measurements are more reproducible than office measurements and more closely associated with hypertension-induced organ damage and cardiovascular risk. 1

Diagnostic Thresholds

• Home blood pressure monitoring (HBPM): >135/85 mm Hg indicates hypertension 2
• 24-hour ambulatory blood pressure monitoring (ABPM): >125/80 mm Hg indicates hypertension 2

White Coat vs. Masked Hypertension

• White coat hypertension: Elevated office BP (≥140/90) but normal out-of-office BP (<135/85 home or <125/80 ambulatory) - occurs in 10-30% of clinic patients 1
• Masked hypertension: Normal office BP (<140/90) but elevated out-of-office BP (≥135/85 home or ≥125/80 ambulatory) - occurs in 10-15% of clinic patients and carries similar cardiovascular risk as sustained hypertension 1

Essential Diagnostic Workup After Confirming Hypertension

Mandatory Laboratory Tests

• Serum sodium, potassium, creatinine, and estimated glomerular filtration rate (eGFR) 1, 2
• Fasting blood glucose 1, 2
• Lipid profile (at minimum total and HDL cholesterol) 1, 2
• Urinalysis with dipstick for protein and blood 1, 2
• 12-lead ECG to detect atrial fibrillation, left ventricular hypertrophy, and ischemic heart disease 1, 2

Physical Examination Focus

• Pulse rate, rhythm, character; jugular venous pressure; apex beat; extra heart sounds; basal crackles; peripheral edema 1
• Vascular bruits (carotid, abdominal, femoral); radio-femoral delay 1
• Enlarged kidneys, neck circumference >40 cm (obstructive sleep apnea), enlarged thyroid 1
• Increased BMI/waist circumference, fatty deposits and colored striae (Cushing syndrome) 1

Symptoms Suggesting Secondary Hypertension

• Muscle weakness, tetany, cramps, arrhythmias suggest hypokalemia/primary aldosteronism 1
• Flash pulmonary edema suggests renal artery stenosis 1
• Sweating, palpitations, frequent headaches suggest pheochromocytoma 1
• Snoring, daytime sleepiness suggest obstructive sleep apnea 1

Common Diagnostic Pitfalls to Avoid

• Never diagnose hypertension based on a single office visit measurement (except BP ≥180/110 with CVD evidence) 1, 2
• Using incorrect cuff size: too small overestimates BP, too large underestimates BP 1, 2
• Failing to allow adequate 3-5 minute rest period before measurement 1, 2
• Talking during BP measurement artificially elevates readings 1, 2
• Not screening for white coat or masked hypertension in borderline cases 1
• Forgetting to assess for orthostatic hypotension in elderly and diabetic patients 1
• Measuring BP over clothing or with unsupported arm position 1