EmergencyEmergency Guide
Cyanosis: Red Flags & Emergency Signs
Central cyanosis (blue lips and tongue) indicates that oxygen saturation has fallen below approximately 85% — this is a medical emergency requiring immediate oxygen and airway assessment.
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If you have this symptom right now
Call 999 (UK) / 112 (EU) / 911 (US) immediately if any emergency warning signs are present. Do not drive yourself. Do not wait to see if it improves.
🚨 Call 999 / 112 Immediately
- ⚠Blue or purple lips and tongue — central cyanosis, SpO₂ <85%, immediate oxygen
- ⚠Cyanosis with stridor or wheeze — upper or lower airway obstruction
- ⚠Cyanosis with chest pain and tachycardia — massive PE or pneumothorax
- ⚠Cyanosis in a newborn — congenital heart disease (duct-dependent circulation)
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- •Peripheral cyanosis of fingertips only in a cold environment is usually benign
- •Persistent central cyanosis despite supplemental oxygen suggests right-to-left cardiac shunt
High-Risk Combinations
When cyanosis occurs together with any of these symptoms, urgency increases significantly:
Conditions to Rule Out Urgently
Massive Pulmonary Embolismemergency
Thrombolysis; haemodynamic support
Tension Pneumothoraxemergency
Needle decompression + chest drain; do not delay for X-ray
Anaphylaxis with Bronchospasmemergency
IM adrenaline 0.5mg; salbutamol nebuliser; oxygen
Condition Authority Pages
Differential diagnosis analyses:
Side-by-side comparisons:
When to Call Emergency Services
- →Any blue or purple colouration of lips, tongue, or face
- →Blue fingers or toes with breathlessness at rest