Smoking - health risks
Reviewed by Dr Gavin Petrie, consultant chest physician
You can eat five portions of fruit and 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?
Term watch
'Cardiovascular' means the heart and circulation.
Cardiovascular disease causes:
- poor circulation
- angina (chest pains)
- heart attacks
- stroke.
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.
Major diseases caused by smoking
Cardiovascular disease
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.
Cancer
Smokers are more likely to get cancer than non-smokers. This is particularly true of lung cancer, throat cancer and mouth cancer, which hardly ever affect non-smokers.
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:
. COPD
Chronic obstructive pulmonary disease (COPD) is a collective term for a group of conditions that block airflow and make breathing more difficult, such as:
Term watch
Chronic means long term, not severe.
Quitting can help
Lung damage from COPD is permanent, but giving up smoking at any stage reduces the rate of decline in lung capacity.
Other risks caused by smoking
Did you know?
A single cigarette can reduce the blood supply to your skin for over an hour.
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.
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.
Passive smoking
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.
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