We all know that smoking is bad for health, but what exactly does it do? How does it affect our bodies? What are the long-term effects of smoking?
Smoking is the main cause of preventable deaths in the UK, accounting for more than 100,000 deaths each year. One in two smokers will die from a smoking-related diseases; most of those deaths will be about 10 years premature. Although the risk of dying from smoking is linked to how many cigarettes you smoke a day, duration of smoking is an even more important risk factor. Smoking's negative effects accumulate and worsen over time, even if you are a light smoker.
Lung damage is the most widely known long-term effect of smoking. Cigarette smoke contains many harmful chemicals that can lead to higher risks of respiratory infections, colds, flu and asthma. Long-term smoking can also cause fatal lung conditions. Smoking causes more than 80% of deaths from lung cancer and chronic obstructive pulmonary disease (COPD). COPD includes emphysema (destroyed lung's air sacs) and bronchitis (inflamed lung's tube linings).
Smoking damages the entire cardiovascular system: reducing blood oxygen levels, increasing the risk of blood clots, raising blood pressure and heart rate, damaging the lining of the arteries and narrowing blood vessels. This forces the heart to work harder to ensure sufficient oxygen circulation. As a result, it increases the risk of conditions such as coronary heart disease, heart attack, stroke, peripheral vascular disease (damaged blood vessels) and cerebrovascular disease (damaged arteries that provide blood to the brain).
Smoking progressively worsens the brain's cognitive function, with heavier smoking and age increasing this impact. Smokers are over 50% more likely to have decreased cognitive function than non-smokers. Perhaps the main cognitive effect of smoking is increased dementia risk. Smoking is one of the main environmental risk factors for dementia, particularly vascular dementia which is caused by brain cell damage due to a reduced oxygen supply.
Smoking damages the mouth and throat, causing relatively minor problems (bad breath, stained teeth) as well as major ones (gum disease, cancer). Smoking is the main cause of oral and throat cancers, including cancer in the lips, tongue, larynx, throat and oesophagus. Smoking can cause gum inflammation and infection (i.e. periodontitis) that ultimately leads to tooth loss. Smokers are over four times more likely to suffer tooth decay and loss than non-smokers.
Smoking affects reproduction and fertility in both men and women. In men, smoking can cause erectile dysfunction, as it restricts blood flow to the penis. It can also reduce sperm count and increase the risk of testicular cancer. In women, smoking can reduce fertility by around 30%, and can cause many pregnancy complications. Smoking can also contribute to early menopause and increased cervical cancer risk.
One of smoking's most obvious targets is the skin. Smoking reduces the amount of oxygen flowing to the skin, accelerating the ageing process and causing discolouration and wrinkles. Smoking also progressively damages bones, potentially causing osteoporosis and greater risk of bone fractures. Smoking reduces bone mineral density by decreasing calcium absorption, lowering levels of vitamin D, reducing body mass and degenerating bone tissue. These issues are particularly prevalent among postmenopausal women. Smoking is also a significant cause of rheumatoid arthritis, especially among men.
While these effects may be overwhelming, the good news is that it's never too late to quit smoking. Smoking causes permanent damage, but some of its long-term effects can be lessened over time, once you quit. Within nine months of quitting, lung function increases by 10%; within 10 years, the risk of lung cancer halves. If you quit before 35, your life expectancy is only slightly less than that of non-smokers.
Quitting is not easy, especially if you have been smoking for a long time. There are medications such as Champix and other aids to help you quit smoking for good are available, when combined with a behavioural change plan and support from your social network.
Cigarettes contain thousands of toxic chemicals. Frequently inhaling nicotine smoke invites the risk of serious, sometimes fatal illnesses, including many types of cancer.