Case Reports

A Ticking Noise From the Chest: Recognition of the Hamman Sign

The authors describe a case of a 21-year-old woman who presented with shortness of breath and exhibited a Hamman sign, an uncommon clinical finding.

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Traditionally, a physician develops a differential diagnosis based primarily (>70%) on the history and the physical examination of a patient.1 While modern medicine has developed with new technological devices and a growing number of diagnostic tests, one must not forget the value of a thorough physical examination.


A 21-year-old woman, in previous good health, presented to the ED with the chief complaint of shortness of breath. She stated that she woke up with acute dyspnea and a stabbing pain on the left side of her thorax, related to her breathing. The patient looked distressed upon presentation.

Her vital signs at presentation were: blood pressure, 150/85 mm Hg; heart rate, 120 beats/min; respiratory rate, 22 breaths/min; and temperature, 100.6°F. Oxygen saturation was 100% on room air.

During physical examination, a loud ticking noise was heard originating from the thorax, even without a stethoscope (an example of the sound can be heard at During auscultation, the ticking noise was prominent in early systole and audible over all parts of the thorax. The sound was only heard when the patient was in the supine position and disappeared when she sat up. It persisted when the patient was holding her breath. Breath sounds were equal and clear bilaterally. There was no subcutaneous emphysema palpable over the thorax or neck region.

Figure 1.

The electrocardiogram and blood results, including D-dimer, were normal. The chest X-ray showed an apical pneumothorax of 1.5 cm on the left side (Figures 1 and 2). There was no evidence of pneumomediastinum or pneumopericardium. The patient received acetaminophen and ibuprofen tablets for pain, and she was discharged home. At the follow-up 2 weeks later, she had no remaining symptoms and the ticking sound had disappeared.

Figure 2.


These loud intermittent noises originating from the thorax were described for the first time at the beginning of the 19th century.2,3 However, it was Louis Virgil Hamman whose name would be linked to this physical examination finding. In 1937 he described typical clicking, crackling, and popping sounds over the precordium, synchronized with the heartbeat. This was usually in combination with subcutaneous emphysema in the neck region. Hamman presumed that the symptoms were due to mediastinal air caused by rupture alveoli or bronchioles, resulting in interstitial emphysema of the lung parenchyma. In addition, air could leak into the pleural space, causing a pneumothorax. He concluded that the clinical findings were pathognomonic for spontaneous mediastinal emphysema, and this physical examination finding became known as the “Hamman sign”.4-11

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