patterns by changing work and sleep times frequently. So, it is not
surprising that this could lead to nausea and other stomach problems.
However, digestive problems also could be caused by lack of nutri-
tious food. For example, sometimes on night shift only junk food
from vending machines is available.
Heart Disease: Heart problems also have been noted more often
among shiftworkers than day workers. For example, Swedish
researchers studied paper mill workers in a small town for several
years. This study is especially meaningful, because the paper mill was
the only employer in town. This made it difficult for the employees to
stop working shifts. Most of them had done shiftwork for most of
their lives. Researchers found that the longer people worked shifts,
the more likely they were to develop heart disease. However, the
way in which the work schedule affects the heart is not at all clear.
Work schedule stress might cause heart disease, but it is more likely a
combination of stress, diet, smoking and drinking habits, other life
stresses, and family history of heart disease.
It is difficult to say exactly how the work schedule fits in with all the
other factors producing heart disease. Earlier we talked about several
different work schedule features that could cause stress and fatigue.
Right now we can only guess about which combination of those fea-
tures has the most impact on a person's health. Constantly shifting
from a day to a night schedule may be one of the stressful factors.
But long work hours, high workloads, and irregular schedules also
can play a role.
Plain Language About Shiftwork
Heart Disease: Heart problems also have been noted more often among shiftworkers than day workers. Work schedule stress might cause heart disease, but it is more likely a combination of stress, diet, smoking and drinking habits, other life stresses, and family history of heart disease.