You know smoking causes lung cancer, emphysema, and heart disease, but you're still lighting up. To help you get on the wagon, we've compiled a list of little known ways your life can go up in smoke if you don't kick the habit.

From an increased risk of blindness to a faster decline in mental function, here are 10 compelling -- and often surprising -- reasons to stick to your commitment. And so you don't have to go it alone, we've also put together a step-by-step guide on how to use WebMD Resources to get started. No butts about it!

Alzheimer's Disease: Smoking Speeds Up Mental Decline

In the elderly years, the rate of mental decline is up to five times faster in smokers than in nonsmokers, according to a study of 9,200 men and women over age 65.

Participants took standardized tests used to detect mental impairment when they entered the study and again two years later. Higher rates of mental decline were found in men and women -- and in persons with or without a family history of dementia or Alzheimer's disease, the researchers reported in the March issue of the journal Neurology.

Smoking likely puts into effect a vicious cycle of artery damage, clotting and increased risk of stroke, causing mental decline, writes researcher A. Ott, MD, a medical microbiologist with Erasmus University Medical Centre in the Netherlands.

The bottom line: The study provides substantial evidence that chronic tobacco use is harmful to the brain and speeds up onset of Alzheimer's disease, Ott says.

Lupus: Smoking Raises Risk of Autoimmune Disease

Smoking cigarettes raises the risk of developing lupus -- but quitting cuts that risk, an analysis of nine studies shows.

Systemic lupus erythematosus -- known as lupus -- is a chronic autoimmune disease that can cause inflammation, pain, and tissue damage throughout the body. Although some people with lupus have mild symptoms, it can become quite severe.

For the analysis, Harvard researchers reviewed studies that examined the relationship between cigarette smoking and lupus. Among current smokers, there was "a small but significant increased risk" for the development of lupus, they report. Former smokers did not have this increased risk, according to the study, which appeared in the March issue of Arthritis & Rheumatism.