Request a Demo
Ziva Health › Health Guides › Asthma
Ziva Health Guides

Asthma.

Asthma affects 300 million people worldwide - yet most attacks are predictable and preventable with good trigger awareness and daily monitoring. Peak flow, HRV, air quality, sleep, and symptom logs together create the early warning picture that stops most attacks before they start.

What is asthma Triggers Peak flow HRV & warning signs Air quality Exercise Sleep Medication How Ziva helps Lab markers FAQ
Isabella · Asthma brief · this week
Peak flow avg
88%
Green zone
Reliever uses
3×
This week
HRV today
61 ms
Stable
Morning peak flow — % personal best
MTWTFSaSu
Isabella · Asthma brief
"Peak flow dipped to 65–72% on Wednesday and Thursday — both high-pollen days (birch count: very high). You used your reliever 3 times this week, all on those two days. HRV dropped 8ms the night before, which may have been an early signal. Pollen season typically peaks for 3 more weeks."
300M
People worldwide have asthma - making it one of the most common chronic conditions globally
95%
Of asthma deaths are preventable with good trigger awareness and access to appropriate medication
24–48h
HRV begins declining before a detectable asthma attack - wearable data may provide an early warning window
Controllable
Well-managed asthma imposes no limit on exercise, work, or quality of life - the goal is zero symptom days
Understanding asthma

What asthma is - and why daily data changes everything.

01
Asthma - airways, inflammation, and why attacks happen.
Asthma is a chronic inflammatory disease of the airways - not just episodic breathlessness. Inflammation causes the bronchial tubes to become swollen, hypersensitive, and prone to bronchoconstriction (muscle tightening around the airway) in response to triggers. This narrows the airway lumen, trapping air and causing the characteristic wheeze, cough, chest tightness, and shortness of breath. Crucially, the inflammatory process is continuous even between attacks - meaning that symptom-free periods don't signal a healthy airway. Effective asthma management targets the underlying inflammation (preventer therapy) not just the acute attack (reliever therapy).
  • Two types: allergic asthma (IgE-mediated, triggered by allergens) and non-allergic asthma (triggered by exercise, cold air, stress, irritants)
  • Many adults have both types - mixed pattern is more common than pure allergic or non-allergic
  • Asthma severity is classified by symptom frequency, reliever use, and lung function - and can change over time
  • Poorly controlled asthma causes airway remodelling over years - permanent structural changes that reduce lung function irreversibly
  • Zero symptom days is the achievable goal with good management - not "managing attacks when they happen"
What Isabella tracks
Isabella logs daily symptoms - wheeze, chest tightness, cough, shortness of breath, night symptoms - alongside reliever use frequency, peak flow, and trigger exposures, building the complete picture your doctor needs.
02
Triggers - finding your personal pattern is the most important thing you can do.
Asthma triggers are highly individual - what provokes severe bronchoconstriction in one person may have no effect on another. The most common triggers are: respiratory infections (the leading cause of exacerbations in all ages), allergens (dust mites, pet dander, pollen, mould), air pollution and particulate matter, exercise (especially cold/dry air), tobacco smoke (first- and second-hand), strong fragrances and chemical fumes, cold air and weather changes, and psychological stress. The only way to identify your personal trigger profile is consistent, longitudinal data - connecting symptom and peak flow changes to documented exposures.
  • Respiratory infections: the most common exacerbation trigger - get flu and COVID vaccinations annually
  • Allergens: test for specific allergies (IgE panel) - knowing your sensitisations guides avoidance and immunotherapy decisions
  • Dust mites: use allergen-proof mattress and pillow covers; wash bedding at 60°C weekly; reduce humidity below 50%
  • Pet dander: no hypoallergenic breeds - all cats and dogs produce Fel d1 and Can f1; HEPA filtration reduces but doesn't eliminate exposure
  • Pollen: real-time pollen counts available - plan outdoor activity around low-count days during season
  • Stress: psychological stress is a genuine asthma trigger - it activates the HPA axis and promotes airway inflammation
What Isabella tracks
Log exposures alongside symptoms and peak flow - Isabella identifies which triggers correlate most strongly with your personal symptom pattern, so you can prioritise the avoidance strategies that will actually make a difference for you.
03
Peak flow - the daily number that predicts attacks before they happen.
Peak expiratory flow (PEF) is the speed at which you can exhale - measured in litres per minute with a simple handheld meter. It directly reflects the degree of airway narrowing. Your "personal best" - measured when your asthma is well controlled - is your baseline. Daily morning peak flow compared to personal best gives three zones: green (80–100%) is good control; yellow (50–80%) signals caution and possible deterioration; red (below 50%) is a severe attack requiring immediate action. The power of peak flow is that it detects deterioration before symptoms become severe - often 12–24 hours in advance.
  • Measure peak flow every morning before any medication - this is your most informative daily reading
  • Establish your personal best over 2–3 weeks when well-controlled - this is your individual baseline, not a population average
  • Morning dip (significantly lower AM than PM peak flow) is a marker of poorly controlled asthma and nocturnal inflammation
  • A consistent pattern of yellow zone readings - even without severe symptoms - warrants a medication review with your doctor
  • Share your peak flow diary at every appointment - it transforms the clinical conversation from symptoms to objective data
  • Smart peak flow meters that sync to apps eliminate the need for paper diaries and enable trend analysis
What Isabella tracks
Log your morning peak flow reading - Isabella tracks your personal best, calculates your daily zone, shows the trend over weeks and months, and flags when sustained yellow-zone readings suggest a medication review is warranted.
04
HRV as an early warning signal - what the research shows.
Heart rate variability (HRV) reflects the balance of the autonomic nervous system - parasympathetic (rest) versus sympathetic (stress). During asthma attacks, sympathetic activation dominates - raising heart rate and reducing HRV. Emerging research shows HRV begins declining 24–48 hours before a clinically detectable asthma exacerbation, likely reflecting the early stages of airway inflammation and autonomic stress that precede the full attack. This creates a potential early warning window. Additionally, people with chronically poorly-controlled asthma have persistently lower HRV baselines, reflecting ongoing systemic inflammatory burden.
  • HRV typically falls 24–48h before a symptomatic asthma exacerbation - a wearable that tracks nightly HRV may provide an early alert window
  • Any acute illness (cold, flu) that precedes an asthma exacerbation will also reduce HRV - the HRV drop is not asthma-specific but is a useful overall stress signal
  • Resting heart rate rises during exacerbations - an elevated morning RHR (above your personal baseline by 5+ bpm) may signal developing airway inflammation
  • Good asthma control - particularly consistent preventer therapy - correlates with higher resting HRV baselines
  • HRV-guided training load management is particularly relevant for athletes with asthma - avoiding hard sessions during early-warning HRV dips may prevent exercise-induced exacerbations
What Isabella tracks
Ziva tracks your nightly HRV and resting heart rate - showing dips relative to your personal baseline. Isabella flags sustained HRV falls in the context of your current trigger exposure, pollen count, and recent illness, to create a contextualised early warning signal.
05
Air quality - the environmental trigger most people underestimate.
Air pollution is one of the most significant and modifiable asthma triggers - and unlike allergens, it's not always visible or obvious. Fine particulate matter (PM2.5) penetrates deep into the lung and triggers intense inflammation in sensitised airways. Ozone, nitrogen dioxide, and sulphur dioxide are the other key pollutants with direct airway irritant effects. High-pollution days correlate with measurable increases in asthma hospital admissions globally. Both outdoor air quality (tracked via real-time indices) and indoor air quality matter - volatile organic compounds (VOCs) from cleaning products, cooking, paint, and furniture can be significant indoor triggers.
  • Check the Air Quality Index (AQI) daily - an AQI above 100 (Unhealthy for Sensitive Groups) warrants outdoor activity modification
  • Peak traffic hours and hot still days produce the highest pollution concentrations in urban areas - avoid outdoor exercise during these windows
  • Indoor air quality often worse than outdoor - cooking (especially gas hobs), cleaning sprays, candles, and incense all produce airway irritants
  • HEPA air purifiers in bedrooms reduce particulate load by 50–80% - particularly useful during high pollen or high pollution periods
  • Wearing a close-fitting mask (N95 or equivalent) during very high pollution events provides partial protection
  • Wood-burning stoves and open fireplaces produce significant PM2.5 - a major indoor trigger often overlooked
What Isabella tracks
Isabella integrates your local air quality index and pollen count data with your symptom and peak flow logs - identifying which pollution and pollen thresholds consistently trigger your airway on your personal data, not population averages.
06
Exercise-induced asthma - how to exercise well, not avoid exercise.
Exercise-induced bronchoconstriction (EIB) affects up to 90% of people with asthma and causes many to avoid exercise entirely - which is the wrong response. EIB occurs because hard exercise requires breathing large volumes of cold, dry air through the mouth, bypassing the nose's warming and humidifying function. This causes airway cooling and water loss, triggering mast cell degranulation and bronchoconstriction. EIB typically peaks 5–15 minutes after stopping exercise. With the right approach, exercise is not just tolerable but actively beneficial for asthma - improving cardiorespiratory fitness, reducing systemic inflammation, and in the long term potentially reducing asthma severity.
  • A 10–15 minute warm-up before intense exercise significantly reduces EIB by inducing a refractory period in the airways
  • Breathing through the nose where possible warms and humidifies air - reducing the cold/dry air trigger
  • Swimming is the most EIB-friendly exercise - warm, humid air reduces the trigger; note: chlorine can be a trigger for some
  • Pre-exercise SABA (short-acting beta-agonist) reliever 15–20 minutes before activity is effective for EIB - discuss with your doctor
  • Cold air significantly worsens EIB - wear a buff or mask over the mouth in winter for outdoor exercise
  • Regular aerobic exercise (when well controlled) reduces asthma severity, eosinophil counts, and reliever use over time
What Isabella tracks
Log exercise sessions and any post-exercise symptoms or reliever use - Isabella identifies which exercise types, intensities, temperatures, and environments trigger EIB in your data, so you can exercise confidently with the right preparation.
07
Sleep and nocturnal asthma - why airways are worst at 4am.
Asthma symptoms and attacks are strongly circadian - they are most severe between 2am and 6am. Multiple mechanisms contribute: cortisol (a natural bronchodilator) is at its lowest overnight, airway inflammation peaks, mucus secretion increases, and sleeping position may increase postnasal drip and allergen exposure (dust mites in mattresses and pillows). Nocturnal symptoms - waking with wheeze, cough, or chest tightness - are a key marker of poorly controlled asthma and are specifically addressed in asthma action plans. Sleep quality is also bidirectional: poor asthma control disrupts sleep, and poor sleep increases airway inflammation.
  • Night symptoms more than twice a month indicate suboptimal asthma control - discuss with your doctor and review preventer therapy
  • Allergen-proof covers for mattress and pillows eliminate the largest allergen reservoir in the home - the most evidence-backed dust mite intervention
  • Gastro-oesophageal reflux (GORD) commonly worsens nocturnal asthma - acid in the oesophagus triggers a vagal airway reflex even without heartburn symptoms
  • Obstructive sleep apnoea (OSA) significantly worsens asthma control - the two conditions overlap and treating OSA improves asthma outcomes
  • Long-acting beta-agonists (LABAs) or once-daily montelukast are specifically useful for controlling nocturnal symptoms
  • Keep windows closed at night during high pollen seasons - pollen counts peak at dawn when windows often open automatically
What Isabella tracks
Log night symptoms and reliever use - Isabella tracks nocturnal asthma frequency, correlates it with evening triggers (late eating, allergen exposure, stress), and shows whether sleep quality changes alongside symptom patterns.
08
Asthma medication - preventers, relievers, and why adherence is everything.
Asthma medication falls into two categories: preventers (inhaled corticosteroids, ICS) that reduce underlying inflammation when taken daily, and relievers (short-acting beta-agonists, SABA) that provide rapid bronchodilation during symptoms. Most under-treated asthma involves inadequate preventer use and over-reliance on relievers - treating symptoms but not the underlying inflammation that causes them. Using a reliever more than twice a week is a signal of poorly controlled asthma, not normal maintenance. Modern combination inhalers (ICS/LABA) and the MART (Maintenance And Reliever Therapy) strategy have substantially improved adherence and outcomes by simplifying regimens.
  • Using a reliever more than twice a week (outside of exercise) is a marker of suboptimal control - the preventer dose likely needs reviewing
  • ICS (inhaled corticosteroids) must be taken daily to work - they have no immediate effect and require weeks to reduce baseline inflammation
  • Inhaler technique is critical and frequently poor - poor technique reduces delivery by up to 80%; a spacer improves delivery significantly for MDI inhalers
  • MART (Maintenance And Reliever Therapy - e.g. budesonide/formoterol as both preventer and reliever) reduces severe attacks by 30–40% vs. fixed-dose ICS + SABA
  • Biologics (dupilumab, mepolizumab, benralizumab) are transformative for severe eosinophilic asthma - dramatically reducing attacks and oral steroid use
  • Annual asthma review with your GP or respiratory nurse is recommended - review technique, control, and whether the current regimen is appropriate
What Isabella tracks
Log reliever use daily - Isabella tracks weekly reliever count as a primary asthma control metric and flags weeks where use exceeds the twice-per-week threshold, prompting you to review preventer adherence and book a medication review.
Isabella in action

Illustrative insights.
The kinds of patterns Isabella finds.

These are illustrative examples. Asthma is driven by personal trigger patterns that are invisible without consistent data. These illustrate the kinds of connections Isabella makes - turning daily logs into the picture that stops attacks before they start.

EM
Emma M., 34*
Allergic asthma · frequent attacks at work
Triggers
The problem

Emma's asthma had been well-controlled for years, but she started having attacks at work 2–3 times a week. Her reliever use tripled. She couldn't identify what had changed.

What Isabella found

Isabella's location and symptom logs showed all attacks occurred in the same 2-hour window on days her colleague wore a specific perfume. Cross-referencing with her office attendance calendar confirmed the pattern across 6 weeks. The trigger wasn't the office - it was a chemical fragrance sensitisation that had developed.

Isabella's insight

"All 7 attacks this month share one feature: you'd logged a 'strong fragrance in office' in the hour before. On fragrance-free office days, peak flow stayed above 85%. On fragrance days, it dropped to 62–70% - yellow zone - within 90 minutes."

Peak flow (fragrance days)
62–70%
Other days
85–92%
JS
James S., 28*
Exercise-induced asthma · runner
EIB
The problem

James had exercise-induced asthma and used his reliever before every run as a precaution. He was frustrated that some runs still triggered symptoms while others didn't - despite identical warm-up and pre-medication routine.

What Isabella found

Isabella's weather and run logs revealed the pattern: symptomatic runs occurred when temperature was below 8°C - cold, dry air overpowered his pre-medication. On runs above 10°C, or on his treadmill, he had zero symptoms. His HRV was also lower on symptomatic run days, suggesting underlying airway sensitivity was already elevated.

Isabella's insight

"Temperature is your EIB trigger - not the run itself. All 9 symptomatic runs were below 8°C. Above 10°C: zero symptoms in 14 runs. On cold days, wearing a buff over your mouth and nose while running could halve the cold-air stimulus."

Attacks below 8°C
9 / 12 runs
Above 10°C
0 / 14 runs
LT
Laura T., 45*
Asthma · night symptoms and poor sleep
Nocturnal
The problem

Laura woke 3–4 nights per week with chest tightness and cough. Her daytime control was fine. Her GP had increased her preventer but the night symptoms persisted.

What Isabella found

Isabella's sleep and symptom logs showed all nocturnal attacks correlated with nights she had eaten within 2 hours of bedtime. Her evening meal included frequent acidic foods (tomato-based sauces, citrus). Isabella flagged this as a classic GORD-triggered nocturnal asthma pattern - acid reflux activating a vagal airway reflex without heartburn symptoms.

Isabella's insight

"Night symptoms are happening on late-eating nights - and never when you finish dinner before 6:30pm. Acid reflux without heartburn is a major nocturnal asthma trigger. Your data strongly suggests GORD-triggered asthma - worth discussing with your GP before any further preventer increase."

Late dinner nights
11 / 12
with symptoms
Early dinner nights
1 / 9
with symptoms
*Stories are inspired by real patient experiences and health patterns observed in care. Names, images, quotes, and certain details have been changed or combined to protect privacy. Individual experiences and outcomes may vary.
Start tracking your asthma with Ziva →
How Ziva helps

Asthma is personal.
Your triggers aren't average.

What's in the textbook tells you the common triggers. What's in your data tells you your triggers - which thresholds set off your airways, which combinations are dangerous, which interventions are actually working. Isabella reads that picture every day.

🌬️
Peak flow logging & zone tracking
Log your morning peak flow - Isabella calculates your zone (green/yellow/red), tracks the trend, and flags when sustained yellow readings warrant a medication review.
💓
HRV early warning signal
Nightly HRV tracked - Isabella flags dips relative to your personal baseline, cross-referencing with trigger exposures to create a contextualised pre-attack warning window.
🌿
Trigger identification
Log exposures - pollen, fragrance, exercise, cold air, stress, food - alongside symptoms and peak flow. Isabella identifies which triggers correlate most strongly with your personal airway response.
💊
Reliever use tracking
Weekly reliever count is the primary asthma control metric. Isabella flags weeks where use exceeds twice per week - the signal that preventer therapy may need reviewing.
🌫️
Air quality & pollen integration
Local AQI and pollen count data integrated with your symptom and peak flow logs - Isabella shows which environmental thresholds consistently affect your airways.
📋
Respiratory appointment reports
30-day summaries of peak flow, reliever use, symptoms, triggers, HRV, and night waking - ready to share with your GP or respiratory nurse for a data-grounded review.
Isabella · 30-day asthma summary
Peak flow ≥80% days
22/30
Reliever uses (month)
11×
Night symptoms
4 nights
Symptom-free days
18/30
HRV (30-day avg)
58ms
Isabella · 30-day summary
"18 symptom-free days — up from 11 last month. Reliever use at 11× is above the 8×/month threshold for well-controlled asthma. Most uses cluster around high-pollen days and your Thursday office days. The GORD pattern from last month looks resolved — 0 night symptoms in the last 10 days since you started finishing dinner earlier."
−40%
Severe attacks with MART strategy vs. fixed-dose ICS
24–48h
HRV early warning window before detectable exacerbation
95%
Of asthma deaths are preventable with good management
Refer Ziva to my provider / care team

Your GP or respiratory nurse isn't on Ziva yet? Send them a link - they'll see your peak flow trend, reliever use, trigger patterns, and night symptoms directly between appointments.

Send my provider a link
Already seeing your provider?

Bring your 30-day Ziva asthma report to your next review - peak flow, reliever use, symptoms, and triggers in one page.

Get your report
Lab & clinical markers

What to test - and what the results mean.

Spirometry (FEV₁ / FVC)
Spirometry measures FEV₁ (forced expiratory volume in 1 second) and FVC (forced vital capacity). An FEV₁/FVC ratio below 70% with reversibility after bronchodilator confirms obstructive airway disease. Baseline spirometry should be performed at diagnosis and repeated if control deteriorates. It distinguishes asthma from COPD and tracks airway remodelling over time.
At diagnosis · repeat if control deteriorates
Blood Eosinophils
Eosinophilic asthma (blood eosinophils above 300 cells/μL) is a specific inflammatory endotype that responds dramatically to biologic therapies. Eosinophil count is now a standard stratification marker - essential if asthma is severe or uncontrolled on standard ICS therapy. Eosinophils above 150 cells/μL also predict a better response to ICS dose increases.
Annual CBC · essential in severe asthma
Total IgE & Specific IgE (RAST)
Total IgE identifies allergic (atopic) asthma. Specific IgE (RAST) testing identifies sensitisation to individual allergens - dust mites, cat, dog, pollen, mould, food. This guides avoidance strategy and eligibility for allergen immunotherapy (desensitisation), which can substantially reduce asthma symptoms over 3–5 years of treatment.
At diagnosis or if allergic asthma suspected
FeNO (Fractional Exhaled Nitric Oxide)
FeNO measures airway eosinophilic inflammation directly - elevated levels (above 40 ppb) indicate active ICS-responsive inflammation. It's used to confirm asthma diagnosis, guide ICS dose adjustment, and assess adherence to preventer therapy. FeNO falls rapidly with ICS use, making it useful for detecting non-adherence in clinic.
Specialist assessment · severe or uncontrolled asthma
Peak Expiratory Flow (Home monitoring)
Daily home peak flow is the most important monitoring tool for most people with asthma - tracking control, detecting deterioration, and guiding self-management action plan decisions. Establish personal best when well-controlled and re-establish after any significant illness or medication change.
Daily monitoring recommended
Skin Prick Test (SPT)
Skin prick testing is the gold-standard method to identify specific allergen sensitisations - faster and more sensitive than blood-based RAST testing. Performed by an allergist. A positive result (wheal above 3mm) combined with a relevant clinical history confirms allergic sensitisation. Guides immunotherapy selection in allergic asthma.
Allergist referral · allergic asthma or polysensitised patients
FAQ

Common questions.

This guide is for informational purposes only and does not constitute medical advice. Asthma management - including medication decisions, action plans, and emergency care - requires individual clinical assessment. Always follow your personal asthma action plan and consult your GP or respiratory specialist for any changes to your treatment.

Isabella AI

Know your triggers.
Stop attacks before they start.

Isabella tracks your peak flow, HRV, reliever use, symptoms, and trigger exposures every day - turning the personal pattern of your asthma into a clear, actionable picture that keeps you in the green zone.

Start for free →