POTS Check
Home screening for Postural Orthostatic Tachycardia Syndrome • iOS & watchOS
Download Now
Available on the App Store
About POTS Check
POTS Check is a home wellness screening tool that helps you explore whether you may have Postural Orthostatic Tachycardia Syndrome (POTS) — a condition affecting blood flow that causes symptoms like dizziness, rapid heartbeat, and fatigue when standing.
Using your Apple Watch and iPhone, POTS Check guides you through the NASA Lean Test, a clinically-recognized screening protocol that monitors your heart rate response when transitioning from lying down to standing.
⚕️ Important Medical Disclaimer
POTS Check is a wellness screening tool, NOT a medical device or diagnostic tool. Results are for informational purposes and discussion with your healthcare provider. This app does not replace professional medical evaluation.
Key Features
- Guided NASA Lean Test: Step-by-step instructions for the 5-minute baseline and 10-minute standing test
- Heart Rate Monitoring: Real-time HealthKit integration with Apple Watch
- Posture Detection: Core Motion sensors ensure proper test positioning
- Age-Based Thresholds: Pediatric (13-19) and adult (20+) POTS screening criteria
- Guest Mode: Try a single test anonymously with no account required
- Secure Account: Full test history with local encryption (ChaCha20-Poly1305)
- PDF Export: Share professional reports with your healthcare provider
- Privacy-First: All data stays on your device
Device Requirements
- iPhone: iOS 18.6 or later
- Apple Watch: watchOS 11.0 or later
- Both devices required for testing
- HealthKit permissions: Heart rate (read), Workout sessions (write)
- Motion & Fitness: Required for posture detection
Two Ways to Use POTS Check
Guest Mode:
- Try a single test with no account required
- Instant results and PDF export
- Data stored in-memory only (cleared when you end session)
- Perfect for first-time users exploring the app
Secure Account:
- Unlimited test history stored locally on your device
- All data encrypted with ChaCha20-Poly1305
- Trend charts and historical analysis
- Professional PDF reports for healthcare providers
- Health Profile: Import baseline vitals from Apple Health (blood pressure, HRV, resting heart rate)
- Completely free — no subscriptions or in-app purchases
Technical Implementation
POTS Check implements the POTS Vocabulary v1.2, a domain-specific ontology that extends the Cascade Protocol Core vocabulary. All test data is serialized to RDF/Turtle format and stored in a local Solid Pod with encryption at rest.
Key technologies:
- Swift 6.0 with strict concurrency
- HealthKit for heart rate monitoring
- Core Motion for posture detection
- RDF/Turtle serialization with W3C PROV-O provenance
- ChaCha20-Poly1305 encryption for Secure Account data
- Modular Swift Package architecture