How smoking affects your lungs

Cigarette smoke contains over 5,000 different chemicals. Find out the impact smoking has on your lungs.

When we breathe in, we are taking the first step in the process that supplies our body with the vital oxygen supplies it needs to function.

We suck air through our mouth and nose, down into our lungs and then through a network of airways to air sacs called alveoli. Here the oxygen is transferred into our bloodstream and around our body.

When we breathe in cigarette smoke the same process occurs. We inhale tobacco smoke through our mouth deep into our lungs, depositing toxins and particles all the way through the network of airways in our lungs right down to the alveoli.

Over the years the impact of the inhaled toxic particles and gases in each cigarette repeatedly damages the lungs and increases a smokers risk of smoking related illnesses.

Here we look at the details of this process and how exactly smoking affects your lungs.

What is in cigarette smoke?

To start, let’s look at what exactly is in cigarette smoke and why it damages our lung health.

The smoke from cigarettes may look to us like a simple grey gas. However, it is more complex than that. Cigarette smoke is a cocktail of over 5,000 chemicals2 in an aerosol (a mixture of solid and liquid particles) and gas form.

Many of these chemicals are carcinogenic, toxic or both. When inhaled these chemicals not only damage the lungs by themselves, but can also mix together to injure our lungs in ways we are still only beginning to understand.1 To make this worse cigarette smoke often contains bronchodilators. Bronchodilators are chemicals that open up the airways in your lungs and can increase the amount of dangerous chemicals that are absorbed.1

Alongside toxic chemicals, cigarette smoke is high in ‘free radicals’.  Free radicals are unstable atoms that can damage cells in our body by causing illness and speeding up the aging process.1

“We’re delighted to be teaming up with NiQuitin on our vital air quality work which will help achieve our overall mission that one day everyone can breathe clean air, with healthy lungs. 

 We know that like smoking, air pollution causes new conditions and exacerbate existing ones. It is an invisible killer that needs urgent action to tackle it.”

Harriet Edwards – Senior Policy Lead, Air Quality, The British Lung Foundation

While cigarette smoke is extremely complex and will vary depending on the type of cigarettes you smoke, some of the common chemicals you are likely to find in cigarette smoke include:

  • Nicotine – this is the chemical that causes the addictive cravings and hit associated with smoking.3
  • Carbon monoxide – replaces the oxygen that would normally be transferred from your lungs to red blood cells, depriving your organs of the oxygen they need.4
  • Acrolein – causes irreversible lung damage, even in low amounts,5 and reduces the ability of your lungs to stay healthy and protect themselves.1  It can cause a sore throat in just 10 minutes.6
  • Formaldehyde – an irritant that can damage little hairs in our lungs, called cilia, that play an important role in removing unwanted materials.1
  • Nitrogen Oxide – linked to high levels of free radicals that can cause illness and premature ageing.1
  • Cadmium – increases the risk of smoking related illness like emphysema.1

How your lungs protect themselves

The average adult is capable of inhaling an extraordinary amount of air. In fact, the average adult will inhale around 10,000 litres of air every single day.1

As each breath we take doesn’t just carry oxygen, it also carries germs and other unwanted materials, our body has developed a complex and elegant set of defences to help protect ourselves.

One important protection is the mucus produced in the airways of our lungs. This mucus helps to keep our lungs clean and well lubricated by catching unwanted materials. The mucus is then wafted by little hairs (called cilia) out of your lungs and into your throat. Here it is either swallowed, most of the time without you even noticing, or can be coughed up.7

These defences provide a good level of protection from lots of the particles we would come across in our day-to-day life. However, the high levels of toxic chemicals in cigarette smoke can overwhelm our lungs defences.

Chemicals, such as Acrolein and Formaldehyde, found in cigarette smoke can also damage the cilia that help to clear unwanted particles from our lungs. Over time this reduces the effectiveness of our lungs defences. You may notice this as you develop a ‘smoker’s cough’. This is as the cilia in your lungs have been damaged and so are less able to clear mucus and particles from your lungs.5

How smoking damages the lungs

Smoking doesn’t just reduce the effectiveness of our lungs defences. The chemicals found in cigarette smoke also play an active role in damaging the airways and alveoli in our lungs.

The airways in our lungs can be extremely small. They are made up of small tubes, known as bronchioles, that can be just the thickness of a human hair.

Smoke from cigarettes irritates the tender tissue in our bronchioles. This can lead to conditions associated with chronic obstructive pulmonary disease (COPD), such as Chronic Bronchitis. Chronic bronchitis is when the bronchioles in our lungs become swollen or inflamed. As the bronchioles become swollen, they narrow and reduce the amount of airflow to and from the lungs.

Long-term inflammation can cause mucus build-up in the lungs and the bronchial tubes to thicken and become scarred.8

Alveoli are air sacs in our lungs. Our lungs can contain an enormous amount of alveoli, up to 300,000,000. They are extremely small, around the width of three human hairs. If we could see alveoli they would look like a bunch of grapes.

Alveoli play an important role in our lungs as they are the point where the oxygen we inhale passes into our bloodstream, and the carbon dioxide we exhale passes the other way. To help with this process they have a thin membrane and are covered in tiny blood vessels, called capillaries, to allow the gas to be transferred to and from our bloodstream.

The combined effect of all these alveoli is our lungs have a huge surface area for transferring gasses between the air in our lungs and our bloodstream.

However, when we smoke the thin membrane of the alveoli is broken down. This makes the alveoli larger and less efficient, reducing the surface area over which our lungs can transfer oxygen and carbon dioxide.

This damage cannot be reversed, once alveoli are damaged they do not mend. This can eventually lead to COPD.9

How smoking affects the lungs of children and teenagers

It is not just adults’ lungs that can be damaged by smoking. Smoking can also have major consequences on the lungs of teenagers, children and unborn babies through either smoking directly or secondhand smoke.

Babies whose mothers smoked during pregnancy may have lungs that develop abnormally. While, teenagers who smoke regularly can develop lungs that never perform at peak capacity and are smaller and weaker than peers that don’t smoke.1

The impact of smoking on your lungs means one of the best things you can do as a smoker for your health is to give up smoking. You can start to experience the benefits of quitting smoking for your lungs in as little as 20 minutes.

This year NiQuitin are joining forces with The British Lung Foundation to protect people’s lungs. Together we will be raising awareness of the damaging ways air pollution affects our lungs and encouraging people to take action to change this. If you would like to find out more about the work we are doing together, visit the British Lung Foundation website.



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