Unless you're living in a cave under the heart of Kentucky tobacco country, you know that smoking isn't exactly the best thing for your health. Scientists have succeeded in associating the habit with everything from countless cancers to bad-hair days, or so it seems with some reports.

Nevertheless, during the 33rd annual Great American Smokeout this Thursday, many of the estimated 43 million adult smokers in the United States will choose to willfully continue smoking while grumbling about how the reported health risks are overblown.

In some respects they are right. A public health message has been spun to imply that not only will smoking surely kill you but it will come to spit on your grave after you die. This has caused a backlash among smokers who mock the health statistics and, persuasively to some, attribute most of smoking's ills to bad genetics.

A reexamination of the statistics might help to clear the air.

Didn't kill grandpa

Surprisingly, fewer than 10 percent of lifelong smokers will get lung cancer. Fewer yet will contract the long list of other cancers, such as throat or mouth cancers. In the game of risk, you're more likely to have a condom break than to get cancer from smoking.

That the majority of smokers beat cancer doesn't make for effective anti-smoking campaigning. So the statistics are turned around: Smoking accounts for 30 percent of all cancer deaths and 87 percent of lung cancer deaths; the risk of developing lung cancer is about 23 times higher in male smokers compared to non-smokers; smoking is associated with increased risk of at least 15 types of cancer; or that smoking causes millions of deaths worldwide.

What does this mean? To the happy and dedicated smoker, it means nothing. The Internet is rife with pro-smoking sites dismissing these kinds of facts. There are billions of people, the argument goes, and they have to die of something, even rare diseases.

The smoking gun

Rarely are simple messages heard, such as the fact that about half of all smokers will die from smoking, and of these, about half will die before or around age 50. These numbers come from a landmark 50-year study of physicians in England, initiated in 1951.

Similarly, research from the ongoing Nurses' Health Study, published in May this year in the Journal of the American Medical Association, finds that 64 percent of nurses who smoked died from smoking-related causes. The life expectancy for a smoker in the United States is about 64, which is 14 years shorter than the national average (which includes smokers), according to the Centers for Disease Control and Prevention.

Going by these numbers it becomes clear that few pastimes, habits or addictions are deadlier than smoking. Only Russian roulette and scorpion juggling come to mind.

Much more than cancer

Part of the problem of the misconception of real risks is the emphasis on smoking and lung cancer. The greater danger is from vascular diseases leading to heart attacks and stroke, which kill more smokers than all cancers combined. Toxins in the tobacco smoke cause inflammation and hardening in the arteries.

Nearly as common as lung cancer among smokers is chronic obstructive pulmonary disease, which entails the narrowing of airways in the lung, largely in the form of chronic bronchitis or emphysema. Bronchitis is a result of smoking-induced inflammation; emphysema stems from cigarette smoking hardening the alveoli, the little sacks in the lungs where oxygen meets blood.

If painful death as a middle-age adult doesn't move you, consider life-quality issues. Smokers get sick more often because smoke paralyzes tiny hair-like structures in the lungs called cilia, which otherwise sweep dirt and bacteria out of your lungs. Smokers have less endurance, particularly sexual endurance, because carbon monoxide replaces oxygen in the blood.

Yet the core argument of ardent smokers remains firm: Smoking doesn't kill everyone. About 50 percent of smokers do reach old age, albeit with diminished taste buds, diminished endurance, diminished eyesight, yellow teeth and bad breath.

Quitting isn't easy. But the first steps are believing the risks are real and deciding whether they are worth avoiding.

Christopher Wanjek is the author of the books "Bad Medicine" and "Food At Work." Got a question about Bad Medicine? Email Wanjek. If it’s really bad, he just might answer it in a future column. Bad Medicine appears each Tuesday on LiveScience.