Understand your sleep apnea and CPAP therapy

Start here Reading Your CPAP Data Learn to read your CPAP data: AHI, leak rate, 95th-percentile pressure, and usage hours explained in plain English, chart by chart. Read the guide → CPAP 95th-Percentile vs Median Pressure: What the Numbers Mean Understand 95th-percentile (P95) and median CPAP pressure, why ResMed uses 95% and Philips 90%, and what your pressure spread says about your settings. 10 min read CPAP Event Types Decoded: Obstructive, Central, Hypopnea & RERA Your AHI is a blend of different events. Learn obstructive vs central apnea, hypopnea, and RERA — and why the same AHI can mean very different things. 8 min read CPAP Flow Limitation: The Hidden Metric Beyond AHI You can have flow-limited breaths all night with an AHI of 0 and still feel exhausted. Learn what flow limitation is and why most apps never show it. 9 min read CPAP Leak Rate: What's Acceptable and How to Fix High Leaks Learn the 24 L/min acceptable CPAP leak threshold, why ResMed and Philips report leak differently, and how large leaks can quietly skew your AHI. 8 min read How to Read Your CPAP Data: A Plain-English Guide to AHI, Leak Rate & Pressure A beginner's guide to reading your CPAP data: AHI, leak rate, 95th-percentile pressure, and usage hours explained in plain English. 9 min read How to Read the CPAP Flow Rate Waveform (Flat-Top Breaths) Learn to read the CPAP flow rate waveform: rounded breaths are healthy, flat-topped breaths signal flow limitation. The most revealing CPAP chart. 8 min read Periodic Breathing & Cheyne-Stokes on Your CPAP Chart Periodic breathing and Cheyne-Stokes show up as a crescendo-decrescendo pattern. Learn what the CPAP flag means and why it needs a doctor's review. 8 min read What Is a Good AHI on CPAP? AHI Ranges and Residual AHI Explained What's a good AHI on CPAP? Learn the residual AHI target under 5, the severity ranges, and why a 'good' AHI can still hide central apneas. 9 min read Why Is My AHI High on CPAP? Causes and How to Find Yours A high AHI on CPAP can mean mask leak, supine sleep, emergent central apneas, or substances. Learn the causes and how your data reveals yours. 8 min read

Start here Understanding Sleep Apnea Sleep apnea explained: symptoms, the obstructive, central, and mixed types, UARS, how AHI and RDI are scored, severity ranges, and key risk factors. Read the guide → AHI vs RDI: Why Two Numbers Measure Your Sleep Apnea AHI vs RDI explained: RDI adds RERAs to the count, so it's always equal to or higher than AHI. Learn why a normal AHI can hide an elevated RDI. 7 min read Central vs Obstructive Apnea: What 'Clear Airway' (CA) Events Mean Clear-airway (central) events behave differently from obstructive ones. Learn what CA events on CPAP mean and when rising centrals need clinician review. 7 min read Cheyne-Stokes Respiration & Periodic Breathing: The Heart Connection Cheyne-Stokes respiration is a central breathing pattern strongly tied to heart failure. Learn what it is, why it matters, and when to see your doctor. 7 min read Obstructive vs Central vs Mixed Sleep Apnea: The Three Types Obstructive, central, and mixed sleep apnea explained: airway collapse vs absent breathing signal vs both — and what your device data can tell you. 7 min read RERA and Flow Limitation: The Events That Don't Show in Your AHI RERAs and flow-limited breaths fragment sleep without counting toward AHI. Learn what a RERA is and why an AHI of 0 doesn't always mean restful sleep. 9 min read Sleep Apnea Symptoms: Signs You Might Need a CPAP Loud snoring, gasping, morning headaches, and daytime sleepiness can all signal sleep apnea. Learn the warning signs and when to get evaluated. 8 min read Sleep Apnea and Your Heart: Hypertension, AFib, Stroke & Diabetes Sleep apnea is linked to high blood pressure, atrial fibrillation, stroke, and type 2 diabetes. Learn the heart connection and when to get screened. 8 min read Sleep Study: In-Lab PSG vs Home Test (and How It Sets Your Pressure) In-lab polysomnography vs a home sleep apnea test: which you need, when PSG is required, and how titration sets your CPAP pressure. 8 min read UARS (Upper Airway Resistance Syndrome): The Diagnosis Your AHI Misses UARS causes RERAs and flow limitation without big oxygen drops, so AHI looks normal but you feel awful. Learn the symptoms and how it's diagnosed. 7 min read Untreated Sleep Apnea Risks: Why the Numbers Matter Untreated sleep apnea is linked to hypertension, heart disease, stroke, and more. Learn the risks — and why consistent, monitored therapy matters. 9 min read What Is Sleep Apnea? Types, AHI, and Severity Explained A medically reviewed overview of sleep apnea: obstructive vs central, what AHI measures, and how mild, moderate, and severe are defined. 8 min read When to See a Doctor About Snoring or Suspected Sleep Apnea Snoring with pauses, gasping, and persistent daytime fatigue are red flags. Learn when to get evaluated and what the path to diagnosis looks like. 8 min read Who Gets Sleep Apnea? Risk Factors You Can and Can't Change Excess weight, male sex, age, family history, and nasal congestion all raise sleep apnea risk. Learn the factors you can change and the ones you can't. 7 min read

Start here CPAP Machines & Devices How each CPAP machine family stores your data — ResMed, Philips, Löwenstein and more — plus what APAP, BiPAP, and ASV modes and comfort settings do. Read the guide → APAP vs CPAP vs BiPAP: Machine Modes and the Data Each Produces CPAP, APAP, BiPAP, and ASV explained: what each mode does, which models use them, and what data each one logs. 8 min read Fisher & Paykel SleepStyle: InfoUSB Data and OSCAR Caveats The SleepStyle uses an InfoUSB stick, not an SD card, and OSCAR derives some metrics from the flow graph. Learn how F&P data works. 7 min read How to Download CPAP Data from Your SD Card (ResMed, Philips, Löwenstein) A practical guide to getting data off your CPAP SD card across ResMed, Philips, and Löwenstein — then where to read it without a desktop install. 9 min read Löwenstein Prisma CPAP Data: How to Read the Under-Served Brand Löwenstein prisma (SMART, 20A, CPAP, 30ST, CR) data access explained — the brand almost no consumer tool reads well, except SomniCharts. 9 min read Philips DreamStation 1 & System One: SD Card Data and How to Read It Unlike the DreamStation 2, the original DreamStation and System One store unencrypted, readable data. Learn where the SD card is and how to analyze it. 8 min read Philips DreamStation 2: Why Its Data Is Encrypted and Your Options The DreamStation 2 encrypts its SD-card data, so OSCAR can't read it. Learn why — and which tools can, now that DreamMapper has shut down. 7 min read Philips Respironics Recall, Explained Neutrally — and Your Data A factual overview of the 2021 Philips foam recall, the silicone replacement, the DreamStation 2 safety notice, and what each means for your data. 7 min read ResMed AirCurve 10 & 11 (VAuto, ST, ASV): Reading Bilevel Data AirCurve bilevel and ASV machines log IPAP, EPAP, and pressure support — uniquely rich data. Learn how to read it and what each mode records. 8 min read ResMed AirSense 10 Data Guide: SD Card and Card-to-Cloud Explained The world's most widely used home APAP. Learn what the AirSense 10 records on its SD card, where the slot is, and how the Card-to-Cloud model differs. 9 min read ResMed AirSense 11 Data: What Your SD Card Holds (and myAir Hides) The AirSense 11 records breath-by-breath data on its SD card in EDF — far more than myAir shows. Learn what's there and how to read it. 9 min read ResMed EPR, Ramp & Climate Control: Verify Your Comfort Settings EPR, ramp, and climate control explained — and how your data proves whether your comfort settings are actually being delivered. 9 min read Switching CPAP Brands? Keep Your Data History Across Vendors myAir and DreamMapper don't follow you when you switch machines. Learn how to keep one continuous data history across ResMed, Philips, and Löwenstein. 8 min read

Start here CPAP Data Tools & Apps Compare CPAP data tools: OSCAR, SleepHQ, myAir, DreamMapper, and online analyzers — what each one shows, what it hides, and which fits your needs. Read the guide → CPAP Compliance Report: How to Get One for Your Doctor or Insurance Need a CPAP compliance report for insurance or a DOT exam? Learn the 4-hour rule, the 70%/30-day standard, and how to generate a shareable report. 9 min read How to Read OSCAR Charts in Plain English (AHI, Leaks, Pressure) Installed OSCAR and stuck on the charts? Learn to read the daily view — AHI, leaks, pressure, flow rate — or let an AI analyzer read it for you. 8 min read How to Read Your ResMed myAir Score (and What It Hides) The myAir score is 0-100 but mostly usage hours — and it hides leak, flow limitation, and event-type detail. Learn what the score means and what it omits. 6 min read OSCAR Alternatives: Best Web-Based CPAP Analysis Tools (2026) Compare web-based OSCAR alternatives — SleepHQ, AirwayLab, and SomniCharts — on device support, waveforms, pricing, and plain-language interpretation. 7 min read OSCAR CPAP Software Guide — and the Easier Cloud Alternative OSCAR is the free, powerful desktop CPAP analyzer — with real friction. Learn what it does, its limits, and the no-install cloud alternative. 8 min read OSCAR vs SleepHQ vs SomniCharts: Which Tool Reads Which Machine A factual support matrix for OSCAR, SleepHQ, and SomniCharts across ResMed, Philips (incl. DreamStation 2), Löwenstein, and Fisher & Paykel. 7 min read Online CPAP Data Analyzer: Upload Your SD Card and Understand Your Night Upload your CPAP SD-card data and get a plain-language read of your night — no desktop install, across ResMed, Philips, and Löwenstein. 9 min read SleepyHead Is Gone — What to Use Now to Read Your SD Card SleepyHead was discontinued in 2019 and became OSCAR. Learn your options for reading CPAP SD-card data today, including a simpler cloud route. 8 min read SomniCharts vs SleepHQ: Cloud CPAP Reporting Compared SleepHQ is the closest cloud competitor. Compare it with SomniCharts on device support, waveform depth, pricing, and AI plain-language interpretation. 7 min read myAir & DreamMapper Limitations: Why Your CPAP App Isn't Enough myAir shows an opaque score; DreamMapper shut down in January 2026. Learn what manufacturer apps leave out and what fuller analysis looks like. 8 min read

Start here Troubleshooting & Optimizing CPAP From symptom to data to safe fix: aerophagia, mask and mouth leaks, dry mouth, congestion, and pressure problems — solved with your own CPAP data. Read the guide → CPAP Aerophagia: Why Your Stomach Bloats and How to Address It Swallowing air on CPAP (aerophagia) causes bloating and gas. Learn the causes, the data signature, and safe steps — without self-adjusting your pressure. 7 min read CPAP Dry Mouth and Mouth Breathing: How to Stop It Tonight CPAP dry mouth is often a sign of mask or mouth leak. Learn the causes, the humidity and chin-strap fixes, and how your leak data connects to it. 8 min read CPAP Mask Leaks & Mouth Leak: Causes, the Data Threshold, and Fixes Mask and mouth leaks ruin comfort and corrupt your AHI. Learn the leak thresholds, why a low AHI can be a lie, and how to fix common leaks. 9 min read CPAP Mask Types and Fit: Nasal, Pillow, and Full-Face Compared Nasal, nasal pillow, and full-face masks each suit different sleepers and leak patterns. Learn how to choose and how mask choice shows up in your data. 8 min read CPAP Nasal Congestion and Stuffy Nose: Causes and Fixes A stuffy nose can make CPAP miserable. Learn the causes of CPAP nasal congestion and the humidification, mask, and ENT-backed fixes that help. 8 min read CPAP Ramp and EPR Explained: Comfort Settings in Your Data Ramp and EPR make CPAP more comfortable — and show up in your pressure data. Learn what they do and how they affect the numbers you see. 8 min read Can I Adjust My Own CPAP Pressure? What the Data Can (and Can't) Tell You Clinicians advise against self-adjusting CPAP pressure. Learn what's defensible: using your data to have an informed conversation with your provider. 8 min read Can't Tolerate CPAP? A New-User Adjustment and Claustrophobia Guide Struggling to adjust to CPAP or feeling claustrophobic? Learn desensitization tips, what alternatives exist, and how to track your progress objectively. 9 min read Central Apneas Showing Up on CPAP: Treatment-Emergent CSA Explained Clear-airway events on CPAP can be treatment-emergent central sleep apnea. Learn what TECSA means, why it often resolves, and when to see your doctor. 8 min read How to Clean Your CPAP Machine, Mask, and Hose (Skip the Gimmicks) The FDA recommends plain soap and water — and warns against ozone/UV CPAP cleaners. Learn a safe cleaning routine for your machine, mask, and hose. 7 min read How to Read CPAP Usage Hours and What 'Compliant' Really Means Usage hours aren't the same as effective therapy. Learn how compliance hours differ from quality therapy and how to read short or fragmented nights. 8 min read Is Your CPAP Pressure Too High or Too Low? Signs and the Data Too-low pressure means snoring and residual events; too-high means aerophagia and exhale fight. Learn the signs and the data that points to the answer. 7 min read Mask Off & Large-Leak Events: Why Your CPAP Report Shows Gaps Mask-off and large-leak periods create gaps and unreliable AHI in your report. Learn why machines can't score events through a big leak. 8 min read Still Snoring on CPAP Despite a Low AHI — What It Means Snoring with a low AHI usually means mild obstruction or a leak — not failed therapy. Learn what the snore channel reveals and how to read it. 8 min read Still Tired on CPAP With Good Numbers? Reasons and Next Steps Low AHI but still exhausted? Hidden flow limitation, RERAs, leaks, or non-apnea causes may be at play. Learn what to check before losing hope. 9 min read Why Does My AHI Change Night to Night? Normal Variation Explained AHI naturally varies night to night. Learn what drives the swings, why one bad night isn't a crisis, and why trends beat single numbers. 8 min read