Do your allergies act up around this time of year? Well, blame it on the tree.

Dr. John Santilli of St. Vincent's Medical Center in Bridgeport, CO says patients "have a dramatic increase in asthma and sinus complaints occurring every winter." That's because the number of airborne mold spores in a typical home increase in the two weeks a real Christmas tree is on display.

Experts at St. Vincent's Medical Center say up to 15 percent of the population is more likely to have their allergies kick up over the holidays.

So, if you're sitting on the couch admiring that newly erected tree and your nose is running and your eyes are watering and you don't know why, the tree you're looking at is probably the answer.