Research indicates that more people die of natural causes during the holiday season than any other time of the year.
It probably has something to do with certain side-effects of winter, such as increased respiratory problems and increased inhalation of airborne particulate matter from the more frequent use of fireplaces, but that's not the whole story. The study revealed a seasonal increase in deaths from natural causes over the winter, but also an additional increase in deaths from natural causes in the period December 25th to January 7th. In fact, whether we're looking at natural deaths or unnatural, the most common days to die are Christmas Day, the day after Christmas, and New Year's Day.
While stress surely has some impact, as well as overindulgence of food and alcohol, scientists think that two other culprits are most likely to have the largest impact. One is people's reluctance to put down their forks and eggnog and seek medical attention when they need it. Two is the changes in medical staffing over the holidays. Staff schedules often change over the holidays, and this may result in less efficient care.