Tobacco: A Seductive Toxin
The main issue with smoking is that it provides a quick reward but leads to a lasting problem.
Text by Aran Luengo Martínez, student at Fedac Anglès School (Girona, Spain) – Eureka Divulgadores 2024 Winner.
26 de noviembre de 2024

When a smoker inhales, nicotine remains in the body for about 72 hours before it fully clears out. During this time, you may feel tense, stressed, and physically uncomfortable. But with just one more puff, you start to feel truly better.
Smoking is more than just a physical addiction; it can feel like it helps you concentrate at work and provides a ready excuse to take regular breaks, which might seem good for your mental well-being. Moreover, it may also feel like a way to socialize and connect with other smokers. Since your lips are among the body’s most sensitive areas, putting something between them can feel incredibly satisfying.
The physical craving may only last three days, but the mental addiction can persist for months.
What Happens Inside a Smoker’s Body?
Now that we’ve outlined this, let’s explore why smoking feels so good and what happens inside your body each time you smoke.
A cigarette is made from dried tobacco leaves mixed with chemicals that help it burn slowly, allowing you to absorb the nicotine, along with flavorings that make it easier to smoke. Tobacco smoke is composed of about 95% gases, such as carbon dioxide and water vapor. The remaining 5% consists of particles known as “tar,” which contain various compounds, including nitrogen and carbon molecules filled with nicotine. When you inhale, billions of these particles interact with anything they encounter, sticking to your tongue, throat, and windpipe.
Your lungs work like inflatable sponges and are lined with tiny hair-like cells called cilia, which are covered by a mucus membrane. These cilia act as filters and barriers, trapping dirt and bacteria in a kind of rhythmic “dance.”
However, tar can settle in the mucus, turning it into a sticky brown substance. This sticky tar paralyzes the cilia, allowing it to move deeper into your lungs, particularly into the alveoli.
The alveoli are tiny air sacs where the act of breathing (gas exchange) occurs. They have very thin walls, making them highly vulnerable, although cilia help protect them. These walls are thin enough for oxygen to enter the blood vessels while carbon dioxide exits. Nicotine passes through these thin walls and enters the bloodstream, reaching the brain so quickly that the effect feels almost instantaneous.

Tobacco plantation.

Healthy lungs.
When nicotine reaches your brain, it triggers the release of many neurotransmitters and hormones that influence your whole body. Epinephrine and cortisol make the heart beat faster and prepare the body for action. Dopamine boosts feelings of happiness and relaxation and helps decrease your appetite. Beta-endorphin reduces pain and stress. Nicotine makes you feel both alert and calm at the same time. As a result, you can concentrate better and feel more awake. Your nerve cells become more sensitive to enjoyable sensations, which helps your body relax. All these effects combined can feel really good.
The brain quickly tries to counteract the effects of nicotine and return to its normal state, which it can manage as long as nicotine is still in your bloodstream. However, when the nicotine disappears, your body overreacts, leading to a significant imbalance. The more you smoke, the harder your body works to regain its normal balance, which is why nicotine is so addictive—you start to rely on it just to feel like yourself.
Smoking might still seem cool to you, but now you rely on it just to feel normal.
The Effect of Nicotine and Other Substances
If that were the only problem, it might not be so bad, right? Unfortunately, nicotine comes with many other harmful chemicals: cadmium, lead, arsenic, hydrogen cyanide, hydrogen peroxide, and nitrogen oxide—all of which can cause damage wherever they go in your body. For example, carbon monoxide reduces the amount of oxygen your blood can carry. In your lungs, cilia become overwhelmed by the tar-covered mucus, leading to cell death. The alveoli, which are very delicate, can’t handle this stress; some may burst like balloons, resulting in irreversible damage to your respiratory system. In response to the tar, goblet cells produce extra mucus, making it more difficult to breathe and leading to coughing.
Your immune system responds by sending macrophages, a type of white blood cell, to destroy tar particles. Smokers have more of these cells in their lungs than nonsmokers because their lungs are filled with waste. However, nicotine slows down these macrophages, making them less effective. Even worse, they release chemicals that harm lung tissue and create small scars. Scarring in your lungs makes it harder to breathe. Nicotine also speeds up your heart rate and narrows blood vessels.
At the same time, harmful chemicals can get trapped in these vessels, causing numerous tiny injuries that turn into scars. These scars lose proteins and can cause blood clots, which further narrow the vessels. This forces your heart to work even harder to keep blood flowing.
In your skin, these chemicals trigger enzymes that break down collagen, the protein responsible for keeping your skin elastic and smooth. This breakdown leads to folds and wrinkles, causing your skin to age much more quickly and making you look older. One of the most concerning effects is on your immune system. Throughout your body, it reacts to these tiny injuries by fighting against an invisible enemy, which can unintentionally damage healthy cells. At the same time, nicotine gradually harms healthy cells and weakens the immune system’s ability to combat real illnesses.

Smoking tobacco increases collagen loss and the appearance of wrinkles.
A General Deterioration of Health
In summary, all your organs are under a lot of stress and can suffer from permanent damage. Over time, fats build up in your blood vessels, causing them to narrow and eventually putting pressure on your organs. Your heart has to beat faster to push blood through these tight spots, which raises your blood pressure significantly. Sometimes, it can beat so hard that fluid leaks into your lungs, making it even harder to breathe.
This also increases the risk of a blood clot blocking an important blood vessel, which can lead to a heart attack. Most smokers eventually develop chronic obstructive pulmonary disease (COPD). As a result, many alveoli become permanently damaged, leaving you short of breath all the time. Once someone is diagnosed with COPD, the condition only gets worse over time.
Finally, there’s cancer. There are two main reasons why smokers are more likely to develop it, both linked to smoking. First, when you smoke, you expose your entire body, especially your lungs, to over seventy different chemicals that can cause cancer. Second, smoking weakens your immune system, making it less effective at preventing and destroying cancer cells.

Smoker’s lungs.
Smoking is one of the most dangerous things you can legally do.
On average, smokers lose about ten years of their lives. This means some might lose only five years, while others could lose up to twenty-five. You can’t predict which group you will fall into. Moreover, smoking often leads to spending more years in poor health.
So, why don’t more people just quit smoking? Many people unfairly see smokers as lacking willpower. However, nicotine is one of the most addictive substances known. Once you start smoking, it’s likely you’ll continue for the rest of your life. Most smokers begin as teenagers. In 2020, only 23% of adults smoked, a decrease from 34% in 2000. Sadly, eight million people died from smoking-related causes last year. The good news is that there are many options available for quitting. Stopping by age 35 can help prevent the loss of any years due to smoking, but quitting later can still add years back to your life. While choosing to smoke is a personal decision, it’s important to understand its consequences.
The best way to avoid addiction is not to start; if you haven’t begun yet, you are better off not smoking at all.
WRITTEN BY Aran Luengo Martínez
Student at Fedac Anglès School, Girona (Spain).
Eureka Divulgadores 2024 Category 1 Winner.
Pictures & Illustrations credits
- Tobacco plantation – Schumacher, Pixabay.
- Healthy lungs – ArtemisDiana, ©iStock.com.
- Collagen loss – TanyaLovus, ©iStock.com.
- Smoker’s lungs – James Heilman-MD, Wikimedia Commons.
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