(CNN)Living with a plugged nose isn't fun, but James Nestor was ready. Plus, it was for science.
While researching his recent book, "Breath: The New Science of a Lost Art," Nestor let Stanford University scientists block his nostrils with silicone and surgical tape to measure the impacts of breathing through his mouth for 10 days.
"We knew it wasn't going to be good, because there's a very firm scientific foundation showing all the deleterious effects of mouth breathing, from periodontal disease to metabolic disorders," Nestor said. The surprise was just how quickly the experiment affected him.
Nestor's blood pressure rose 13 points, edging the writer into stage one hypertension. Measurements of heart rate variability showed his body was in a state of stress. His pulse went up, and he stumbled around in a mental fog.
He also snored for hours each night, developing obstructive sleep apnea. His blood oxygen levels dropped.
"We had no idea it was going to be that bad," Nestor said. "The snoring and sleep apnea was so dramatic, and it came on so quickly, that everyone was pretty floored."
What Nestor learned, aside from the hazards of being a research subject, was that mouth breathing can ruin a good night's sleep.