“The results of nearly all experimental data show that the effect of diminished barometric pressure upon the human organism is to lower the blood pressure. This result is not transient, but permanent. While the pressure may rise slightly it does not reach its former level.”

On the other hand, according to the same source …

“There is evidence to show that hemorrhage cases, especially those of fatal tendencies, occur most frequently in patients with cardiac and arterial disease, and that these cases are more fatal in higher than in lower altitudes.”