Nasal flaring

The widening of the nostrils during inspiration, reflecting increased respiratory effort and recruitment of accessory mechanisms to reduce airway resistance, often indicating respiratory distress, particularly in infants and young children.

Causes

• Respiratory infections

  • Bronchitis

  • Pneumonia

  • Bronchiolitis

  • Viral upper and lower respiratory tract infections

• Obstructive airway causes

  • Asthma exacerbation

  • Croup

  • Epiglottitis

  • Foreign body aspiration

  • Other causes of airway narrowing

• Pulmonary causes

  • Acute respiratory distress syndrome (ARDS)

  • Chronic lung diseases

  • Pulmonary edema

  • Severe hypoxemia

• Cardiovascular causes

  • Heart failure

  • Cardiogenic pulmonary congestion

• Anaphylaxis or allergic airway reactions

• Intense physical exercise

• Neuromuscular disorders causing respiratory muscle fatigue

• Metabolic conditions causing compensatory hyperventilation