Association between High Blood Pressure in the Emergency Department and Cryptogenic Hemoptysis.

Hemoptysis is a common cause of emergency department (ED) visits. There is little data about the role of systemic hypertension as a cause of hemoptysis. The aim of this study was to evaluate the association between systemic blood pressure and the unknown etiology of hemoptysis. This retrospective study included consecutive patients who visited the ED owing to hemoptysis and underwent a chest computed tomography between January 2011 and June 2021. Details of the initial blood pressure at the ED visit were compared between two groups with identified and unidentified causes of hemoptysis. In total, 1105 adult patients were included. The etiology of hemoptysis was identified in 1042 patients (94.3%) and remained unidentified in 63 patients (5.7%). The percentage of patients with severe hypertension was significantly higher in patients with unidentified causes of hemoptysis than in those with identified causes (35% vs. 11%, p < 0.001). In multivariate analysis, age, ever-smoker, and initial systolic blood pressure were significantly associated with hemoptysis of unidentified causes. Although further studies are needed, our findings suggest a possible association between high blood pressure and cryptogenic hemoptysis.