Maybe this is why they're called "cold" sores.

Outbreak seasonal trends.

While it's impossible to know exactly why herpes lip lesions have become known as cold sores, we will state that it seems likely that people suffer with them more so during the cold-weather months than at other times of the year.

Our graph makes a pretty good case for this claim.

As evidence, take a look at the following chart.

Based on 5 years of data, it appears that search volume on the world-wide-web for the term "cold sores" tends to peak right at year's end.

What's the explanation?

We'd suggest that there could be two obvious reasons why this phenomenon exists, both due to known risk factors for cold sores.

1) As their name implies, having a "cold" sore or "fever" blister often coincides with times when a person has some type of illnesses that stresses their health. And as we all know, cold and flu outbreaks frequently occur during the winter months.

2) It also seems likely that the cold-weather months, with their onset of holidays and demanding year-end school and work schedules, set the stage for people experiencing psychological and emotional stress. These factors are also known triggers for cold sore outbreaks.

Our comments about our graph.

We don't make a claim that we've performed any type of statistical testing in regard to our observation, or the conclusions we've drawn from it. We consider this phenomenon simply a curiosity.

We will say, however, that while we did notice this seasonal effect when evaluating the keywords "cold sores," we didn't when researching words that referenced other types of mouth sores and ulcers.

We'll also state that it seems unlikely to us that many people would be searching for the term 'cold sores' unless that person actually had one and was seeking a remedy.

Our comments about the data we used.

For a data source, we simply evaluated Google search statistics on a per-year basis (2004 - 2009) for the keywords "cold sores."

For each calendar year, we valued the month with the highest search volume at 100 and then calculated the relative value for the lesser months. We then combined the five years of data (all years receiving equal weighting) and again normalized the month with the highest total to 100 and calculated the relative value for the lesser months.