1. As a part of the Tecumseh Health Study, blood pressure was recorded during three physical examination cycles covering a span of 8 years. Change in blood pressure was evaluated with reference to a variety of epidemiological variables.
2. A strong tendency was shown to regress toward the mean; high pressures tended to fall, and low pressures to rise.
3. In those with increasing systolic pressure, when categorized by percentage change rather than change in absolute manometer readings, steepness of rise was not different in those initially high as compared with those initially low in systolic pressure.
4. Change in pressure was not related to initial degree of obesity, but was definitely related to change in absolute weight. Those whose pressure increased tended to increase in weight, and conversely.
5. Reported medical treatment had little demonstrable effect upon the proportion of persons initially hypertensive who had a decline in blood pressure 8 years later.
6. No relationship was seen between spouses in blood pressure change. Children's pattern of change did not relate to parents' pattern although the general increase in these young ages probably obscured the comparison.
7. A variety of socioeconomic, occupational as well as physiological variables were compared with patterns of change with no definite relationships found.