Hemoptysis and breath-holding diving.

Objective: We aim to present one case with hemoptysis. Pulmonary barotrauma of descent (lung squeeze) has been described in breath-hold divers when the lung volume becomes smaller than the residual volume, with the effect of increased ambient pressure.

Methods: We report one case of hemoptysis in a breath-hold diver who dove for exercise of military action.

Results: The patient's hemoglobin and hematocrit levels were 7.3 g/dL and 26%, respectively. The computed tomography of thorax obtained 5 hours after the diving event revealed images suggestive of hemoptysis. The diagnosis of hemoptysis was made based on the diver's history and computed tomography findings. All of the divers performed voluntary diaphragmatic contractions at the beginning of their ascent, while their mouths and noses were closed.

Conclusion: We suggest that the negative intrathoracic pressure attributable to the forced attempt to breathe along with voluntary diaphragmatic contractions contributes to hemoptysis, since it may damage the pulmonary capillaries.