12 Reasons to Really Quit Smoking

Video: Secrets to a Better You: How to Stop Smoking for Good

8. It hurts bones. Smoking weakens the body's scaffolding and is a serious risk factor for osteoporosis, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. It's been shown to fritter away bone density in postmenopausal women and to hike the risk of hip fractures in both sexes, according to the 2004 Surgeon General's Report. (People who endure hip fractures are 12 to 20 percent more likely to die than those who don't, the Report notes, though there are ways osteoporosis sufferers can protect themselves.) Smokers may also experience slower healing of broken bones and wounded tissues than do nonsmokers.

9. It may injure the insides. Sure, cigarettes may be smooth to inhale, but they can rough up the digestive system, leading to heartburn, peptic ulcers, and possibly gallstones, according to the National Institute of Diabetes and Digestive and Kidney Diseases. What's more, current and former smokers have an elevated risk of developing Crohn's disease, a condition characterized by inflammation in the digestive tract and causing pain and diarrhea, says NIDDK.

10. It may stifle sleep. Feeling groggy despite a night's slumber might be a problem for those who light up: A February study in Chest found that smokers are four times more likely to get nonrestorative sleep than those who don't smoke, and researchers deemed nicotine the likely culprit. They theorized that its stimulant properties deal smokers a double blow, making it difficult to fall asleep and also potentially sending the body into nicotine withdrawal during the night. (Half of the chemical's effect wears off within two hours.) Since inadequate shut-eye can invite health problems, consider forgoing cigarettes for the sake of your sleep.