We’ve known the dangers of smoking for decades, but how exactly does tobacco harm us?
The Toxicity of Tobacco
Let’s explore what happens when tobacco enters the body and how we benefit from quitting smoking.
With every puff, cigarette smoke releases more than 5,000 chemicals that impact the body’s tissues. First, tar—a black, sticky substance—begins to coat the teeth and gums, damaging enamel and eventually causing tooth decay.
Over time, cigarette smoke destroys nerve endings in the nose, leading to a loss of smell.
In the trachea and lungs, smoke increases toxicity, contributing to chronic diseases like bronchitis and emphysema. It does so by damaging tiny hair-like structures called cilia that filter the air we breathe.
Smoke then fills the alveoli, the small air sacs responsible for oxygen and carbon dioxide exchange between the lungs and the bloodstream.
A toxic gas called carbon monoxide penetrates the mucus membranes and binds to hemoglobin in the blood, displacing oxygen that should be circulating throughout the body. This is one reason smoking can cause shortness of breath.
Within 10 seconds, nicotine—a stimulant in tobacco—reaches the brain, triggering the release of dopamine and other neurotransmitters, including endorphins, which create pleasurable sensations and lead to addiction.
Nicotine and other tobacco chemicals constrict blood vessels and damage their delicate inner lining, restricting blood flow.
These vascular effects cause arteries to narrow and platelets to become stickier, increasing the risk of blood clots, heart attacks, and strokes.
Many chemicals in tobacco can cause dangerous mutations in DNA, leading to cancer. Additionally, substances like arsenic and cadmium interfere with DNA repair, weakening the body’s ability to fight cancer.
In fact, one in three cancer deaths in the U.S. is caused by smoking. And it’s not just lung cancer—smoking can lead to cancer in various tissues and organs, impair vision, weaken bones, reduce fertility in women, and cause erectile dysfunction in men.
Immediate Health Benefits of Quitting Smoking
For those who quit smoking, the physical benefits begin almost immediately.
- After 20 minutes: Heart rate and blood pressure return to normal.
- After 12 hours: Carbon monoxide levels stabilize, improving the blood’s oxygen-carrying capacity.
- After 1 day: Heart attack risk decreases, and blood pressure and heart rate stabilize.
- After 2 days: Nerve endings related to smell and taste start to recover.
- After 1 month: Lung function improves, reducing coughing and shortness of breath. The delicate cilia in the lungs and trachea begin regenerating within weeks, fully recovering after nine months, boosting resistance to infections.
- After 1 year: Cardiovascular disease risk drops by half, as blood vessels function more efficiently.
- After 5 years: Blood clot risk declines significantly, and the stroke risk continues to drop.
- After 10 years: The chance of developing fatal lung cancer decreases by 50%, as the body’s DNA repair mechanisms recover.
- After 15 years: The risk of coronary heart disease aligns with that of a non-smoker.
Quitting smoking can cause anxiety and stress due to nicotine withdrawal, but these effects are usually temporary. Fortunately, quitting has become easier with the development of helpful tools.
Nicotine replacement therapy (NRT) options—such as gum, patches, lozenges, and sprays—can aid the quitting process. These products stimulate nicotine receptors in the brain, reducing withdrawal symptoms without introducing harmful chemicals from cigarettes.
Support groups, cognitive behavioral therapy, and moderate exercise can also help smokers quit successfully.
Quitting smoking allows your body to heal and leads to a healthier, happier life.
Quit smoking now!
Watch the full video “How Does Smoking Affect the Body?” on TED-Ed’s YouTube channel, with nearly 21 million subscribers.