Respiratory rate (RR) is the number of breaths a person takes per minute — a core vital sign and one of the earliest signs of clinical deterioration. The normal adult range is 12–20 breaths/min.
definitions
- Normal: 12–20 breaths/min
- Tachypnea: > 20
- Bradypnea: < 12
- RR > 30 → red flag
- RR < 8 → respiratory arrest zone
ABCs
- Check O₂ saturation + vitals
- Recheck RR manually
- Observe
- Work of breathing
- O₂ saturation
- Mental status
Causes
classify as respiratory, compensatory, or neuro/drug-related
| Category | Tachypnea | Bradypnea |
|---|---|---|
| Pulmonary | Pneumonia, PE, asthma/COPD exacerbation, pneumothorax | — |
| Cardiac | Acute heart failure, ACS | — |
| Metabolic | DKA, metabolic acidosis, sepsis | Severe hypothyroidism |
| Neurological / Drug | Anxiety, pain, brain injury | Opioid/sedative overdose, raised ICP |
| Other | Fever, anemia, hyperthyroidism, pregnancy | End-of-life physiology, neuromuscular disorders |
workup
- ABG if severe / hypoxic / hypercapnia concern
- CXR or lung ultrasound
- ECG if cardiac / PE concern
- CBC, U&E, CRP, lactate
- Troponin / D-dimer if indicated
initial management
- Ensure airway patency
- Give oxygen if hypoxic
- Sit patient upright
- Stop/reverse offending drugs (e.g. opioids → naloxone)
- Treat underlying cause:
- Sepsis → antibiotics + fluids
- PE → anticoagulation (once confirmed/suspected appropriately)
- DKA → insulin + fluids
- COPD/asthma → bronchodilators ± steroids
- Escalate early if:
- RR > 30
- RR < 8
- Increasing work of breathing
- Altered mental status
Last reviewed · May 2026