But the list doesn't stop there.
Dr. John Spangler, professor of family and community medicine at Wake Forest Baptist Medical Center, says he has found that many people have been told cigarettes are bad, but haven't been told why. The harsh reality, he says, is that cigarettes cause damage throughout the body.
High blood pressure, diabetes
In addition to lung cancer and heart disease, Spangler says smoking can contribute to high blood pressure, type 2 diabetes, stroke, gum disease, arthritis, and even erectile dysfunction.
Cigarette smoke is damaging, in part, because it can contain as many as 9,000 different chemicals, many of which are toxic, and as many as 70 that have been linked to cancer.
“When you smoke, these various chemicals get into the bloodstream, are carried to all parts of the body and go right to the most susceptible cells,” Spangler said. “That’s why there’s such a wide array of negative effects from cigarettes.”
Carbon monoxide
Even carbon monoxide, the gas that results from the incomplete burning of any carbon-related material, damages the body. Too much of it interferes with the blood's capacity to transport oxygen throughout the body, including to important areas of the brain and heart. That's often why a heavy smoker suffers from shortness of breath, and even heart failure.
Tars found in cigarette tobacco are harmful because they can build up in the lungs, inflaming the linings of blood vessels and other soft tissues. It can reduce the body's ability to ward off infection, slow the healing process, and release free radicals -- a major element in the development of cancerous tumors.
Falling smoking rates
Fortunately, smoking rates in the U.S. have been steadily declining, in part because more people area aware of health issues, but also because taxes have made smoking a very expensive habit.
According to the Centers for Disease Control and Prevention (CDC), 42% of U.S. adults smoked in 1965. By 2014, the percentage had dropped to 16.8%.
Spangler says nicotine is far from the most harmful substances in cigarettes, but it is one of the most dangerous, because it's addictive. It's why people continue to smoke, even when they know the health facts.
To quit, Spangler suggests using nicotine gun or patches while trying to work on the habits -- like having a cigarette after a meal -- that keep many people lighting up and wrecking their health.