ME/CFS

ME/CFS Tracking Built Around Crash Prevention

PEM crash diary with 72-hour trigger lookback. Activity logging by exertion type and intensity. Energy envelope pacing. Fluid tracking. Everything ME/CFS patients need to stop guessing and start managing.

Built for the 1.3 million Americans living with Myalgic Encephalomyelitis / Chronic Fatigue Syndrome. No more boom-bust cycles.

Download Free See the Tools

What is ME/CFS?

Myalgic Encephalomyelitis / Chronic Fatigue Syndrome is a complex, multi-system disease characterized by profound fatigue that is not improved by rest, post-exertional malaise (PEM), cognitive dysfunction, and unrefreshing sleep.

The hallmark symptom is post-exertional malaise (PEM) -- a disproportionate worsening of symptoms following physical, cognitive, or emotional exertion. PEM can be delayed by 24-72 hours, making it extremely difficult to identify triggers without systematic tracking.

The Numbers

1.3 million Americans affected
Up to 91% remain undiagnosed
Average 5+ years to diagnosis
25% of patients are housebound or bedbound

There is no FDA-approved treatment for ME/CFS. Management centers on activity pacing -- staying within your energy envelope to prevent PEM crashes. Leo provides the tools to make pacing data-driven instead of guesswork.

Severity Levels

Mild

Can work reduced hours. Activities significantly limited but still possible. Functioning at roughly 50% of pre-illness capacity.

Often misdiagnosed as depression or anxiety

Moderate

Unable to work. Mobility limited. Requires rest periods throughout the day. Significant cognitive impairment.

Most commonly diagnosed severity

Severe

Mostly housebound. Can only do minimal daily activities. Requires significant assistance. Severe cognitive dysfunction.

Often wheelchair-dependent

Very Severe

Bedbound. Unable to perform any daily tasks independently. Extreme sensitivity to light, sound, and touch.

Requires full-time care

Severity can fluctuate. Many patients cycle between levels depending on activity and PEM episodes.

Management Philosophy

STOP · REST · PACE

The three pillars of ME/CFS management. Leo's tools are designed around this framework -- helping you recognize when to stop, enforcing rest during crashes, and providing the data to pace effectively.

STOP

Recognize early warning signs before a crash hits. Rising heart rate, increasing brain fog, and growing fatigue are signals to stop activity immediately -- not push through.

REST

When a crash occurs, complete rest is essential. Not 'light activity' -- actual rest. Leo's crash banner and timer help you track recovery and resist the urge to resume too early.

PACE

Stay within your energy envelope by tracking exertion across all categories. The goal isn't to do more -- it's to find a sustainable baseline that doesn't trigger PEM crashes.

Symptom Tracking

Track Every ME/CFS Symptom

ME/CFS is a multi-system disease with symptoms spanning neurological, autonomic, immune, and energy systems. Leo tracks them all with severity ratings and correlation analysis.

Cardinal

Post-exertional malaise (PEM)
Severe fatigue (not relieved by rest)
Unrefreshing sleep
Reduced activity tolerance

Neurological

Brain fog / cognitive dysfunction
Difficulty concentrating
Word-finding problems
Short-term memory issues
Sensory overload

Autonomic

Orthostatic intolerance
Dizziness on standing
Heart rate irregularities
Temperature dysregulation
Night sweats

Immune

Sore throat
Tender lymph nodes
Flu-like malaise
New food/chemical sensitivities
Recurrent infections

Complete Toolkit

Your Complete ME/CFS Toolkit

Everything ME/CFS patients need to manage their condition -- from crash prevention to doctor visits -- in one app.

PEM Crash Diary

Killer Feature

The centerpiece of ME/CFS management. Log post-exertional malaise episodes with severity (1-10), onset type (immediate, delayed, or next-day), symptom tags (brain fog, muscle pain, dizziness, fatigue, sore throat), and duration tracking. Each crash auto-links to suspected triggers via the 72-hour lookback engine so you can see exactly what pushed you over the edge.

Severity rating 1-10
Onset type classification
Symptom tag selection
Duration tracking
Auto-linked trigger analysis
Crash history timeline

Activity Logger with Intensity Tracking

Log physical, cognitive, social, and emotional activities with 1-5 intensity levels and exertion type classification. Understanding what counts as exertion -- not just exercise, but a phone call, a shower, or processing a stressful email -- is the foundation of effective pacing. Leo captures it all.

Physical activity logging
Cognitive exertion tracking
Social energy costs
Emotional exertion capture
1-5 intensity levels
Exertion type classification

72-Hour Trigger Lookback Engine

When you log a PEM crash, Leo automatically scans all activities from the previous 72 hours and highlights likely triggers based on your personal crash history. Over time, it builds a personalized trigger profile -- learning which activity types and intensity levels most reliably precede your crashes.

Automatic 72-hour activity scan
Personal crash history matching
Trigger probability ranking
Personalized trigger profile
Pattern learning over time
Activity-to-crash correlation

Energy Envelope Pacing

Visualize your daily energy budget versus actual exertion across cognitive, physical, and emotional categories. The energy envelope concept is central to ME/CFS management -- staying within your limits prevents the boom-bust cycle that leads to crashes. Leo makes the invisible visible.

Daily energy budget visualization
Cognitive energy tracking
Physical energy tracking
Emotional energy tracking
Budget vs actual comparison
Boom-bust cycle prevention

Fluid & Electrolyte Tracker

Many ME/CFS patients have co-occurring orthostatic intolerance and benefit from increased fluid and electrolyte intake. Track water (mL), sodium (mg), and potassium (mg) with progress rings and quick-log supplement presets including common electrolyte brands.

Water intake tracking (mL)
Sodium tracking (mg)
Potassium tracking (mg)
Progress ring visualization
Supplement presets
Daily goal setting

Active Crash Banner & Timer

When a PEM crash is logged, a persistent banner appears showing current severity, elapsed duration, and active symptoms. This serves as both a tracker and a reminder to rest -- not push through. The banner stays visible until the crash is marked as resolved.

Persistent crash status banner
Severity display
Duration timer
Active symptom list
Rest reminder
Resolution tracking

Trigger Pattern Insights

See which exertion types most frequently precede your crashes, with average delay times between activity and PEM onset. Discover whether physical, cognitive, social, or emotional exertion is your biggest risk factor -- and at what intensity level things tend to go wrong.

Exertion type frequency analysis
Average delay time tracking
Risk factor identification
Intensity threshold detection
Personal pattern dashboard
Trend analysis over time

Lab Tracking

Track condition-relevant labs including CBC, CMP, thyroid panels, cortisol, inflammatory markers (CRP, ESR), and immune panels. Set personal target ranges and visualize trends over time so your specialist can see the full picture alongside your symptom data.

CBC & CMP panels
Thyroid panel tracking
Cortisol monitoring
Inflammatory markers (CRP, ESR)
Personal target ranges
Trend charts over time

ME/CFS Rarely Travels Alone

Leo's multi-condition system lets you track ME/CFS alongside common comorbidities. Because managing overlapping conditions shouldn't require 5 separate apps.

POTS / Dysautonomia

In Leo

Orthostatic intolerance is extremely common in ME/CFS. Many patients meet criteria for both conditions.

Fibromyalgia

In Leo

Widespread pain and fatigue overlap significantly. 50-70% of ME/CFS patients also meet fibromyalgia criteria.

IBS

In Leo

GI symptoms including bloating, nausea, and food sensitivities are reported by the majority of ME/CFS patients.

Migraine

In Leo

Headaches and migraine are among the most common co-occurring symptoms in ME/CFS.

EDS

In Leo

Ehlers-Danlos Syndrome shares fatigue, pain, and dysautonomia features. Part of the EDS/POTS/MCAS overlap.

MCAS

Mast cell activation symptoms including flushing, hives, and GI distress frequently co-occur with ME/CFS.

Depression

In Leo

Secondary depression is common due to the life-altering nature of ME/CFS. Distinct from primary depression.

Long COVID

Post-COVID ME/CFS is now a leading cause of new diagnoses. Identical symptom profile in many patients.

How Leo Compares

Most health apps weren't built for ME/CFS. Generic symptom trackers miss the nuance of PEM tracking, activity pacing, and crash prevention. Leo was designed specifically for this.

Feature	Leo	Generic Apps	Paper Tracking
PEM Crash Diary with Severity Tracking
72-Hour Trigger Lookback
Activity Logger by Exertion Type
Energy Envelope Visualization
Fluid & Electrolyte Tracking
Active Crash Banner & Timer
Trigger Pattern Insights
Lab Tracking with Targets
Apple Watch Integration
Doctor-Ready PDF Reports
Multi-Condition Support
Gamification & Rewards
Free (No Premium Paywall)

= available in some apps

Identify Your PEM Triggers

PEM triggers are highly individual and can be delayed up to 72 hours. Leo's lookback engine helps you discover your personal patterns across physical, cognitive, emotional, and environmental categories.

Physical

Physical overexertion
Standing too long
Household chores
Exercise
Travel

Cognitive

Screen time
Reading
Problem solving
Multi-tasking
Decision making

Emotional

Emotional stress
Conflict
Grief
Excitement
Social events

Environmental

Poor sleep
Infections
Heat or cold
Loud noise
Bright lights

Stop Guessing. Start Pacing with Data.

Leo gives you the tools to understand your energy limits, identify your triggers, and prevent PEM crashes -- with clean reports to share with your specialist.

Free to download. No premium paywall for ME/CFS features.

Download Free See All Conditions