Exposure to cigarettes over a long period may change the shape of your heart.
Researchers at the University of Illinois at Chicago studied rats exposed to cigarette smoke. The researchers discovered that in just five weeks of exposure to smoke, the heart's main pumping chamber, called the left ventricle, began to change in shape.
The rats also had high levels of hormones known to cause several different physiological changes. Researchers are not sure how these results apply to humans, but they say it is worth further study.