Smoking: Heavy smokers have higher rates of heart disease and cancer, but research shows that even one or two cigarettes a week can increase the risk of bronchitis, coughs, and asthma attacks.

Tanning: One million people are diagnosed with skin cancer every year. While we accumulate the majority of our sun damage as children, any UV exposure during adulthood adds to that risk. Even the occasional use of a tanning bed triples a person’s chances of developing melanoma. Stick to the spray-on stuff.

Being a Couch Potato: Regular exercise does everything from reducing the risk of breast cancer to preventing diabetes to managing stress. The surgeon general recommends at least 30 minutes of moderate physical activity most days, so try to stay active for at least that long. Take a walk, play hoops, run after the dog, or jump rope with the kids.