Smoking – health risks
Reviewed by Dr Patricia Macnair, GP
|Cigarettes contain more than 4000 chemical compounds and at least 400 toxic substances.|
You can eat five portions of fruit or veg a day and exercise regularly – but healthy behaviour means little if you continue to smoke.
The message that 'smoking is bad for you' is an old one, so not everyone gives it their full attention.
Below we list the health risks of smoking.
Why quit smoking?
Most people know that smoking can cause lung cancer, but it can also cause many other cancers and illnesses.
Smoking directly causes over 100,000 deaths in the UK each year and contributes to many more.
How do cigarettes damage health?
Cigarettes contain more than 4000 chemical compounds and at least 400 toxic substances.
When you inhale, a cigarette burns at 700°C at the tip and around 60°C in the core. This heat breaks down the tobacco to produce various toxins.
As a cigarette burns, the residues are concentrated towards the butt.
The products that are most damaging are:
- tar, a carcinogen (substance that causes cancer)
- nicotine is addictive and increases cholesterol levels in your body
- carbon monoxide reduces oxygen in the body
- components of the gas and particulate phases cause chronic obstructive pulmonary disorder (COPD).
The damage caused by smoking is influenced by:
- the number of cigarettes smoked
- whether the cigarette has a filter
- how the tobacco has been prepared.
Smoking affects how long you live
Research has shown that smoking reduces life expectancy by seven to eight years.
Did you know?
On average, each cigarette shortens a smoker's life by around 11 minutes.
Of the 300 people who die every day in the UK as a result of smoking, many are comparatively young smokers.
Non-smokers and ex-smokers can also look forward to a healthier old age than smokers.
Major diseases caused by smoking
Cardiovascular disease is the main cause of death due to smoking.
Hardening of the arteries is a process that develops over years, when cholesterol and other fats deposit in the arteries, leaving them narrow, blocked or rigid. When the arteries narrow (atherosclerosis), blood clots are likely to form.
Smoking accelerates the hardening and narrowing process in your arteries: it starts earlier and blood clots are two to four times more likely.
Cardiovasular disease can take many forms depending on which blood vessels are involved, and all of them are more common in people who smoke.
A fatal disease
Blood clots in the heart and brain are the most common causes of sudden death.
- Coronary thrombosis: a blood clot in the arteries supplying the heart, which can lead to a heart attack. Around 30 per cent are caused by smoking.
- Cerebral thrombosis: the vessels to the brain can become blocked, which can lead to collapse, stroke and paralysis. Damage to the brain's blood supply is also an important cause of dementia.
- If the kidney arteries are affected, then high blood pressure or kidney failure results.
- Blockage to the vascular supply to the legs may lead to gangrene and amputation.
Smokers tend to develop coronary thrombosis 10 years earlier than non-smokers, and make up 9 out of 10 heart bypass patients.
The link between smoking and lung cancer is clear.
- Ninety percent of lung cancer cases are due to smoking.
- If no-one smoked, lung cancer would be a rare diagnosis – only 0.5 per cent of people who've never touched a cigarette develop lung cancer.
- One in ten moderate smokers and almost one in five heavy smokers (more than 15 cigarettes a day) will die of lung cancer.
The more cigarettes you smoke in a day, and the longer you've smoked, the higher your risk of lung cancer. Similarly, the risk rises the deeper you inhale and the earlier in life you started smoking.
For ex-smokers, it takes approximately 15 years before the risk of lung cancer drops to the same as that of a non-smoker.
If you smoke, the risk of contracting mouth cancer is four times higher than for a non-smoker. Cancer can start in many areas of the mouth, with the most common being on or underneath the tongue, or on the lips.
Other types of cancer that are more common in smokers are:
Chronic obstructive pulmonary disease (COPD) is a collective term for a group of conditions that block airflow and make breathing more difficult, such as:
Chronic means long term, not severe.
- emphysema – breathlessness caused by damage to the air sacs (alveoli)
- chronic bronchitis – coughing with a lot of mucus that continues for at least three months.
Smoking is the most common cause of COPD and is responsible for 80 per cent of cases.
It's estimated that 94 per cent of 20-a-day smokers have some emphysema when the lungs are examined after death, while more than 90 per cent of non-smokers have little or none.
COPD typically starts between the ages of 35 and 45 when lung function starts to decline anyway.
Quitting can help
Lung damage from COPD is permanent, but giving up smoking at any stage reduces the rate of decline in lung capacity.
In smokers, the rate of decline in lung function can be three times the usual rate. As lung function declines, breathlessness begins.
As the condition progresses, severe breathing problems can require hospital care. The final stage is death from slow and progressive breathlessness.
Other risks caused by smoking
Did you know?
A single cigarette can reduce the blood supply to your skin for over an hour.
- Smoking raises blood pressure, which can cause hypertension (high blood pressure) – a risk factor for heart attacks and stroke.
- Couples who smoke are more likely to have fertility problems than couples who are non-smokers.
- Smoking worsens asthma and counteracts asthma medication by worsening the inflammation of the airways that the medicine tries to ease.
- The blood vessels in the eye are sensitive and can be easily damaged by smoke, causing a bloodshot appearance and itchiness.
- Heavy smokers are twice as likely to get macular degeneration, resulting in the gradual loss of eyesight.
- Smokers run an increased risk of cataracts.
- Smokers take 25 per cent more sick days year than non-smokers.
- Smoking stains your teeth and gums.
- Smoking increases your risk of periodontal disease, which causes swollen gums, bad breath and teeth to fall out.
- Smoking causes an acid taste in the mouth and contributes to the development of ulcers.
- Smoking also affects your looks: smokers have paler skin and more wrinkles. This is because smoking reduces the blood supply to the skin and lowers levels of vitamin A.
Smoking and impotence
For men in their 30s and 40s, smoking increases the risk of erectile dysfunction (ED) by about 50 per cent.
Did you know?
The British Medical Association estimates that up to 120,000 men have ED because of smoking.
Erection can't occur unless blood can flow freely into the penis, so these blood vessels have to be in good condition.
Smoking can damage the blood vessels and cause them to degenerate: nicotine narrows the arteries that lead to the penis, reducing blood flow and the pressure of blood in the penis.
This narrowing effect increases over time, so if you haven't got problems now, things could change later.
Erection problems in smokers may be an early warning signal that cigarettes are already damaging other areas of the body – such as the blood vessels that supply the heart.
Smoking and others
There are many health-related reasons to give up cigarettes – not just for smokers, but to protect those around you.
Babies born to mothers who smoke during pregnancy are twice as likely to be born prematurely and with a low birth weight.
The 'side-stream' smoke that comes off a cigarette between puffs carries a higher risk than directly inhaled smoke.
Children who grow up in a home where one or both of their parents smoke have twice the risk of getting asthma and asthmatic bronchitis. They also have a higher risk of developing allergies.
Infants under two years old are more prone to severe respiratory infections and cot death.
For adults, passive smoking seems to increase the risk of lung cancer, but the evidence for an increased risk of heart disease is not yet conclusive.
Thinking about quitting?
As well as reducing your risk of getting a smoking-related illness, there are other benefits to quitting smoking.
- General health improves – tiredness and headaches can be linked to smoking.
- Your sense of taste and smell improve.
- Your heart will be less strained and work more efficiently.
Stopping smoking is the single biggest thing you can do to improve your health, but it's a difficult task.
Smokers who are trying to kick their habit may be disappointed to find there's no single quit method that guarantees success.
The weight of evidence suggests that smokers should set a date to stop, and do their best to quit completely from this point.
On average it takes four to five attempts to give up, and there are a number of things that can help willpower.
- Nicotine replacement treatment (NRT) in the form of gum, skin patches or nasal spray.
- Zyban (bupropion) is a medicine that's licensed to help smoking cessation.
- Champix (varenicline): a medicine that mimics the effect of nicotine in the body, and so reduces the urge to smoke and also reduces withdrawal symptoms. Varenicline can double your chance of successfully quitting
- Behaviour modification programmes.
- Alternative therapies such as acupuncture and hypnosis.
Research shows that people who take part in a full 'quit smoking' programme, including behavioural therapies and medication, may increase their chance of successfully quitting from about 3 per cent on willpower alone to over 30 per cent.
Other people also read:
Smoking – cutting down or quitting: tackling physical and psychological addiction.
Medicines to help you quit: medicines can double your chances of quitting.
Based on a text by Dr Carl J Brandt
Last updated 02.11.2011