Smoking can have a devastating effect on your health and well being. About half of all smokers will die of an illness related to the habit; smoking is responsible for 80% of deaths from lung cancer, and is thought to be the cause of a quarter of deaths from all types of cancer.

Despite the health effects being common knowledge, advertising and sponsorship bans, cigarettes being hidden from plain sight in shops and harrowing illustrations now being included on packaging, quitting is still incredibly difficult for most smokers.

A 2016 report from NHS Digital revealed that as of 2014 approximately 19% of British adults smoked. This is a huge drop from the 1970s when nearly half of the adult population were smokers, but still a sizeable minority. Alarmingly, the same report found that the highest percentage of smokers were young adults in the 16-34 age range, representing a quarter of all adults in that group.

So how does smoking affect different parts of the body? And why is it so addictive?

  1. The heart
  2. The lungs
  3. The digestive system
  4. The mouth
  5. The skin
  6. The bones
  7. The reproductive system
  8. Mental health
  9. Addiction

The heart

Smoking increases the levels of carbon monoxide in your body, reducing the amount of oxygen in your blood. Toxins in the tobacco also thicken the blood. This forces your heart to work harder to pump the blood around your body.

Nicotine encourages the adrenal glands to generate adrenaline. This helps to provide the nicotine ‘rush’ that smokers crave. Adrenaline raises the heart rate and blood pressure, putting the heart under strain.

The arteries (the tubes that enable blood to circulate around the body) are damaged by smoking, causing them to become lined with a mixture of fatty substances and scar tissue called atheroma.

This buildup narrows the arteries, restricting the flow of blood around the body and to vital organs. A piece of the atheroma may break off and cut off the blood supply completely, causing a blood clot. These clots can lead to stroke, angina, and heart attacks.

Smoking increases your risk of developing cardiovascular and circulatory disease.

The lungs

We’ve already mentioned how smoking is the cause of the majority of lung cancer cases. It is among the hardest types of cancer to survive, with only five percent of people surviving longer than ten years.

Tobacco contains thousands of chemicals, and over 70 of them are carcinogenic; substances that are thought to cause cancer. The smoke fumes, and the tar it leaves behind, start to damage the tissue in the lungs. They do not only damage the DNA in the lungs, but as time passes they affect the ability of the tissue in the lungs to repair itself. This greatly increases the risks of cancerous growths.

Smoking is also to blame for over 80% of deaths from chronic obstructive pulmonary disease (COPD). This term covers a number of diseases which affect the lungs, such as bronchitis and emphysema.

Emphysema is caused when smoke damages the small air sacs in the lungs. You can develop bronchitis when you damage the tissue in the lungs and airways (bronchi), and they become inflamed and lined with mucus. The symptoms include a persistent cough, wheezing, recurrent chest infections and feeling breathless, and these will get progressively worse over time.

While giving up will not repair the damage to the lungs caused by smoking, it will prevent them from becoming damaged further, and symptoms may be able to be managed by medication.

The digestive system

Smokers are at increased risk of developing cancer of the stomach, as well as in the kidneys, liver, oesophagus, colon, rectum and pancreas.

Around one in five cases of stomach cancer is caused by smoking; when smoke is inhaled, some of it is swallowed, which damages stomach tissue leading to tumour growths.

Give up smoking considerably decreases the chances of these cancers developing over time.

Smokers are also thought to be more susceptible to other medical complications such as Crohn’s disease, pancreatitis, gallstones, GORD (gastroesophageal reflux disease), heartburn and peptic ulcers.

The mouth

Smoking can also reduce someone’s sense of taste, bad breath and lead to yellowing or blackening of the teeth. But more seriously, smokers are prone to cancer in the mouth, lips, throat, neck, vocal cords and tongue. According to the Mouth Cancer Foundation, three quarters of mouth cancer cases are caused by smoking, and this risk increases even further in those who also drink alcohol.

While smokeless products such as chewing tobacco, betel quids and snus may reduce the risk of some other cancers, they increase the chances of developing mouth or throat cancer.

Cigar and pipe smokers are more likely to develop these cancers than cigarette smokers, as they tend to inhale the smoke into their mouths rather than their lungs.

The skin

The diminished levels of oxygen in the blood and the toxins in nicotine can leave skin looking pale, grey and dried out. Skin will wrinkle prematurely because the blood vessels narrow and cannot get enough oxygen or important nutrients, such as vitamin A or vitamin C, to the skin cells requiring them.

The bones

The toxins which enter the body when smoking upsets the delicate balance of hormones in the system; impeding the production of oestrogen which is needed to maintain strong bones, and raising the levels of a hormone called cortisol, which can affect bone density.

It can be particularly risky for women, who are already more likely to develop brittle bones (osteoporosis) than men, especially during the menopause, when the levels of oestrogen in the body naturally start to fall.

The reproductive system

For men, smoking can inhibit the blood supply to the penis, and cause impotence. It can reduce sperm count, harm the DNA of sperm that are produced, and increase the risk of testicular cancer.

In women, fertility rates are greatly reduced with one study finding that women who smoke more than ten cigarettes a day were around a third less likely to get pregnant.

During pregnancy, women who smoke are more likely to miscarry or give birth prematurely. Women who smoke are also at increased risk of developing cervical cancer.

Mental health

Aside from the stress caused by nicotine addiction, such as cravings and withdrawal symptoms, smoking engenders the production of an important substance called dopamine, which is released into the brain and helps relieve stress and enhances feelings of pleasure. After a while, the brain starts to stop using its own mechanism for producing dopamine, leaving the smoker increasingly dependent on their habit for their supply.

A 2014 report had strong findings to suggest that people who smoked on a daily basis were twice as likely to develop schizophrenia than non-smokers due to the harm nicotine can cause to the brain.

Why do we become addicted?

When cigarette smoke is inhaled, nicotine reaches the brain within a matter of seconds. This nicotine ‘rush’ increases the levels of noradrenaline and dopamine in the brain, reducing stress and engendering feelings of relaxation.

After a while the body develops a tolerance to nicotine, so to get the same  pleasurable feelings, a person will need to smoke more. Not being able to smoke causes feelings of irritability and stress, as well as withdrawal symptoms.

Cigarettes can also become part of a daily routine, which makes it even harder to give up. Smokers may be used to having a cigarette first thing in the morning or after a meal, or with a group of friends outside work. People also turn to smoking as a form of comfort or as a way with dealing with stressful situations or anxiety.

How can I stop?

To maximise your chances of success of quitting for good, there are local stop smoking services all over the country which are managed by the NHS and are free. They can offer support and help work out the best type of treatment for you.

You will usually be advised to use prescription or nonprescription treatments alongside one to one or group support from your stop smoking service.

The prescription medications used to help quit smoking are Varenicline (marketed as Champix) and Bupropion (Zyban).

Alternatively you may be advised to use nicotine replacement therapy (NRT). These include nicotine patches, gum, inhalers, sprays and tablets.

E-cigarettes are becoming increasingly popular as a quitting aid; although they contain nicotine, they do not contain the harmful tar or carbon monoxide fumes associated with normal cigarettes. They are not currently available on the NHS, and the benefits of them are not yet fully clear, but many people have reported them as helpful in giving up smoking.

While quitting can be tough, there are support networks in place for those who want to give up, and the benefits of being smoke free will be life-changing.

Page last reviewed:  10/03/2022