What happens to a human being if the air pressure is too high or too low?
Barometric pressure is the weight of a column of air above the surface of the Earth. A barometer measures how many inches of mercury in a tube this column of air supports. The standard atmosphere is 29.92 inches of mercury. At sea level, this pressure exerts about 14.7 pounds per square inch. Air pressure is one of the most benign weather phenomena and its effects on the human body are minor, even at the extremes.
At Chicago, the record high air pressure is 30.98 inches, recorded on Feb, 16, 1989; the record low is 28.70 inches on March 12, 1923. The difference between the two extremes is 2.28 inches and it represents only about one pound per square inch, or a change of only 2,160 feet in elevation.