Words describing discomfort associated with the act of breathing (dyspnea) can be found in the hieroglyphics of Mesopotamia (3300 B.C.), in the Harappa civilization in the Indus valley (2500 B.C.), and the Smith and Ebers papyri of ancient Egypt (1534 B.C.). These words were pragmatic, acquired meaning from common usage, and were destined to change with progressive understanding.
