More and more does one become impressed with the fact that patients with arteriosclerosis are very often those who take life too seriously and either from ambition or from an exalted sense of duty lead especially strenuous lives. Not always are these persons addicted to drug or liquor habit. Many are rather abstemious in their habits. It is not so often that we see as a victim of arteriosclerosis, the carefree person who laughs his way through life without worrying about the morrow. He is not so prone to arteriosclerosis. Worry is a far more potent cause of breakdown than actual manual work. It is the rule to find thickened arteries among neurasthenics. This may be only part of a generalized degeneration of all tissue in the body. The blood pressure in such persons is usually low. So many men of our better class live under a continuous mental strain in the business world. The increase in arteriosclerosis cases is real, not apparent. The intense mental strain seems to cause a marked increase in blood pressure (for short periods of mental effort this has been proved) over a period of time sufficient to cause permanent changes in the vessel walls. The same sequence of events repeats itself; high tension, arterial strain, compensatory thickening, hypertrophied heart, etc. Certainly the character of the arterial tissue has much to do with the determination of degenerative changes which may result from the action of one or more of the etiologic factors. =Muscular Overwork= Muscular overwork is to be reckoned with as an etiologic factor. One sees it especially among the laboring class in both whites and negroes. Possibly other factors, as alcohol and coarse heavy food, contribute to the early arterial degeneration. Hypertrophy of the heart occurs in athletes, and statistics gathered among the oarsmen especially, show a relatively high mortality at the different decades traceable to the high tension produced while in training. This question deserves more consideration than has been accorded it. =Renal Disease=