Abstract
There are many isolated facts, some of which are well established, concerning blood pressure. Discussions of the subject which occur from time to time bring out new and interesting facts and call attention to the variations in medical opinion. During this period of developing knowledge, it is essential to gather all the details possible concerning blood pressure, so that eventually a direct route may be laid out through the maze of information. Without considering the possible changes in the blood as an effect, we accept the ultimate condition in hypertension as being due to the reduced cross-section of the arteriolar tree. The theory that caliber reduction from arteriolar sclerosis causes hypertension must be mentioned. This condition of constriction, however, may be discussed as the cause or result of hypertension, and the possibility must be taken into consideration that chronic mild infection, severe generalized infection or focal infection causes endarteritis with