The characteristic physical signs of asthma include: loud prolonged polyphonic expiratory wheeze and adventitious sounds such as rhonchi. Presence of wheeze is indicative of airway narrowing; however, the absence of wheeze indicates a silent lung characteristic of status asthmaticus delineated by widespread obstruction that results in significant airflow reduction and insufficient enough to produce a wheeze.^[1]

Physical examination may be normal or can be characteristically present with a loud polyphonic expiratory wheeze.^[1][2]

• Increased heart rate in acute severe episode

• Pulsus paradoxus (a fall of SBP between 10-20mmHg during inspiration) in moderately severe episode
• Pulsus paradoxus (a fall of SBP greater than 20-40 mmHg during inspiration) in acute severe episode and imminent respiratory failure

• Increased respiratory rate greater than 30 cycles per minute in moderately severe and acute severe episodes

• Profuse sweating in imminent respiratory failure
• Severe hypoxia resulting in central cyanosis and hypoventilation in imminent respiratory failure

• Conjunctival congestion as a consequence of constant rubbing are suggestive of associated allergic rhinitis.

• Nasal examination is mandatory to rule out associated conditions such as, aspirin sensitivity or allergic rhinitis.
• Transverse crease on nose as a consequence of constant rubbing and pale swollen nasal mucosa are suggestive of associated allergic rhinitis.

• Prolong end-expiratory wheeze
• In between attacks, chest is clear and no abnormal physical signs may be detectable.

• Use of accessory muscles of respiration such as sternocleidomastoid and scalene muscles
• Hyper-resonant lungs
• Loud prolonged expiratory wheeze with a reduced inspiration to expiration ratio
• Vesicular breath sounds with prolonged respiration

• Patient has to sit upright with arms extended to support the upper chest (tripod position) that assist the use of accessory muscles of respiration
• Use of accessory muscles of respiration

• Paradoxical thoraco-abdominal breathing
• Wheeze and breath sounds are typically absent secondary to severe airway obstruction, representing a silent chest which is an ominous sign.

• Persistent scattered rhonchi

• Triad of asthma, nasal polyps and rash is indicative of aspirin sensitivity.
• Presence of clubbing in asthma may be secondary to interstitial lung disease.