Blood Pressure Monitoring
Track systolic and diastolic pressure with AHA category classifications
What is Blood Pressure?
Blood pressure is the force of blood pushing against artery walls, measured in millimeters of mercury (mmHg). It has two components:
- Systolic pressure - The top number, measuring pressure when the heart beats (contracts)
- Diastolic pressure - The bottom number, measuring pressure when the heart rests between beats
Example: A reading of 120/80 mmHg means 120 systolic and 80 diastolic.
Why Blood Pressure Matters
Sustained high blood pressure (hypertension) is a major cardiovascular risk factor:
- Increases risk of stroke and heart attack (MI)
- Can damage blood vessels, heart, kidneys, and other organs
- Often has no symptoms ("silent killer")
- Treatable with lifestyle changes and medications
Blood Pressure Categories (AHA)
The American Heart Association defines these categories (AHA Guidelines):
Normal
<120 / <80 mmHg
Maintain healthy habits to keep blood pressure in this range.
Elevated
120-129 / <80 mmHg
At risk of developing hypertension. Lifestyle changes recommended.
Stage 1 Hypertension
130-139 / 80-89 mmHg
Consult clinician. Lifestyle changes and possibly medication.
Stage 2 Hypertension
≥140 / ≥90 mmHg
Requires medical treatment. Combination of medications and lifestyle changes.
Hypertensive Crisis
>180 / >120 mmHg
Emergency: Seek immediate medical attention.
How Cardio Analytics Uses Blood Pressure Data
- Stores paired systolic/diastolic readings - Complete BP measurements with timestamps
- Overlays AHA category bands - Visualize which category your readings fall into
- Trend analysis - Track BP changes over days, weeks, and months
- Medication correlations - See how antihypertensive medications affect your BP
- Alerts for elevated readings - Personalized thresholds based on AHA guidelines or your clinician's targets
- Write-back to HealthKit - Manual BP entries sync to Apple Health for consistency
📊 Track multiple readings: BP varies throughout the day. Take measurements at the same time daily for consistent tracking.
HealthKit Data Types
Cardio Analytics reads blood pressure data from Apple HealthKit using these identifiers:
bloodPressureSystolic- Systolic blood pressure (mmHg) (Apple Docs)bloodPressureDiastolic- Diastolic blood pressure (mmHg) (Apple Docs)
Systolic and diastolic readings are correlated using HealthKit's correlation API to ensure paired measurements.
Tips for Accurate Blood Pressure Measurement
- Use validated devices - FDA-cleared or clinically validated BP monitors
- Measure at the same time daily - Morning and evening are ideal
- Rest before measuring - Sit quietly for 5 minutes before taking a reading
- Proper positioning - Arm at heart level, feet flat on floor, back supported
- Avoid caffeine, exercise, smoking - 30 minutes before measurement
- Take multiple readings - Average 2-3 readings taken 1 minute apart
- Use the correct cuff size - Cuff should cover 80% of upper arm
Scientific References
- American Heart Association. Understanding Blood Pressure Readings. https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings
Track Your Blood Pressure with Cardio Analytics
Monitor BP trends with AHA category classifications and medication correlation analysis.
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