Green Zone — Everyday Control
Peak flow near personal best means asthma stays quietly managed.
- 80–100%: PEF Range (of personal best)
- 0–1: Symptom Score (rare or none)
- <2/wk: Reliever Use (occasional only)
- None: Controller Change (stay the course)
What defines green zone
Peak flow sits eighty to one hundred percent of personal best.
Green zone means asthma is under everyday control.
Daily controller routine
Inhaled corticosteroid taken every day, exactly as prescribed.
Peak flow monitoring habit
Morning peak flow readings catch early drift before symptoms.
Yellow Zone Entry — Early Warning Signs
Peak flow slips or symptoms rise — the plan calls for caution.
- 50–79%: PEF Range (of personal best)
- 3–5: Symptom Score (noticeable increase)
- Rising: Reliever Use (more frequent puffs)
- Review: Trigger Check (colds, allergens, exercise)
Recognizing the shift
Cough, wheeze, or chest tightness appear more than usual.
Yellow entry signals the plan should be watched closely.
Peak flow as an early signal
A drop below eighty percent often precedes felt symptoms.
What to track next
Log symptoms and peak flow twice daily until stable.
Yellow Zone Action — Step Up Therapy
The written plan tells the patient exactly how to self-adjust.
- 50–64%: PEF Range (of personal best)
- Add doses: Reliever (per plan schedule)
- 2×: ICS Dose (double the usual dose)
- 1–2 days: Reassess Window (check for improvement)
Doubling inhaled steroid
Doubling ICS dose is a common first-line yellow zone step.
Written plans let patients self-adjust without waiting for a visit.
Adding the reliever
Short-acting reliever puffs are added on a set schedule.
When action fails
No improvement in two days means escalate toward red zone.
Red Zone Entry — Medical Alert
Peak flow under half of best marks a dangerous asthma flare.
- <50%: PEF Range (of personal best)
- 8–9: Symptom Score (severe distress)
- Poor: Reliever Response (little relief felt)
- Watch: Danger Signs (lips, ribs, speech)
Red zone thresholds
PEF below fifty percent defines the red danger zone.
Red zone entry means the flare is no longer self-limiting.
Severe symptom signs
Trouble speaking full sentences signals a severe attack.
Immediate next step
Red zone always triggers the emergency action steps.
Red Zone Action — Emergency Response
Emergency reliever, oral steroid, and urgent care save lives here.
- 4–6 puffs: Reliever Dose (every 20 minutes)
- Start now: Oral Steroid (per plan instructions)
- Immediate: Call for Help (urgent or emergency care)
- Call 911: No Improvement (do not delay)
Emergency reliever dosing
Repeated reliever doses are given every twenty minutes.
Delaying emergency care in the red zone can be fatal.
Oral corticosteroid burst
A short oral steroid course is started immediately.
Seeking urgent care
Go to urgent care or call emergency services now.