The Big Number, 02062018. Health&Science. (The Washington Post/The Washington Post)

It's true that fewer Americans smoke cigarettes today than in decades past, but about 38 million still smoke daily or some of the time, according to a new report from the Centers for Disease Control and Prevention. Overall, the percentage of adults who smoke fell from 20.9 in 2005 to 15.5 percent in 2016. And those who still smoke reportedly puff away on fewer cigarettes each day than before. However, smoking is blamed for 1 of every 5 deaths in the United States each year, and it puts at risk not just those who smoke but also those who are exposed to secondhand smoke. The possible health effects of smoking are numerous, including lung disease and lung cancer, heart disease and stroke. Smoking also can cause problems with your immune system, bone density and vision, studies have found, and it has been linked to cancers throughout the body. According to the Campaign for Tobacco-Free Kids, health-care costs attributed to smoking total $170 billion a year. Although quitting is not easy, studies have found that doing so can put you on the path to better health right away: improved circulation and blood pressure, easier breathing, better senses of taste and smell. Also, cancer risk goes down as long as you stay smoke-free. Best of all: You'll live longer.

— Linda Searing