There are multiple factors that can contribute to the development of<unk> , including sex (male), genetic factors, prior development of<unk> , ascent rate, cold exposure, peak altitude, intensity of physical exertion, and certain underlying medical conditions (e.g., pulmonary hypertension). Anatomic abnormalities that are predisposing include congenital absence of pulmonary artery, and left-to-right intracardiac shunts (e.g., atrial and ventricular septal defects), both of which increase pulmonary blood flow.<unk> -susceptible <unk> -s) individuals were also found to be four times more likely to have a patent foramen ovale (PFO) than those who were<unk> -resistant. There is currently no indication or recommendation for people with PFO to pursue closure prior to extreme altitude exposure. In studies performed at sea level,<unk> -s people were found to have exaggerated circulatory response to both hypoxia at rest and during exercise. In these individuals, the pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) were shown to be abnormally<unk> . Microneurographic recordings in these individuals developed a direct link between PAP rise and sympathetic nervous system over-activation, which could explain the exaggerated response to hypoxia in these persons. Endothelial tissue dysfunction has also been linked to development of<unk> , including reduced synthesis of NO (a potent vasodilator), increased levels of endothelin (a potent vasconstrictor), and an impaired ability to transport sodium and water across the epithelium and out of the alveoli. Data on the genetic basis for<unk>  susceptibility is conflicting and interpretation is difficult. Genes implicated in the development of<unk>  include those in the renin-angiotensin system (RAS), NO pathway, and hypoxia-inducible factor pathway (HIF). Future genomic testing could provide a clearer picture of the genetic factors that contribute to<unk> .
High-altitude pulmonary edema
High-altitude cerebral edema
Decompression sickness
Chronic mountain sickness
Monofixation syndrome
Athletic heart syndrome
Pulmonary-renal syndrome
Cardiorenal syndrome