Cigarette smoke contains the following noxious substance:
Nicotine
Nicotine is a drug that stimulates the brain. If you are a regular smoker, when the blood level of nicotine falls, you usually develop withdrawal symptoms such as craving, anxiety, restlessness, headaches, irritability, hunger, difficulty with concentration, or just feeling awful. These symptoms are relieved by the next cigarette. So, most smokers need to smoke regularly to feel 'normal', and to prevent nicotine withdrawal symptoms.
Tar which contains many chemicals
These deposit in the lungs and can get into the blood vessels and are carried to other parts of the body. Cigarette smoke contains over 4000 chemicals, including over 50 known carcinogens (causes of cancer) and other poisons.
Carbon monoxide
This chemical affects the oxygen-carrying capacity of the blood. In particular, in pregnant women who smoke, this causes a reduced amount of oxygen to get to the growing baby. This is thought to be the most important cause for the bad effects of smoking on the growing baby.
Diseases
Lung cancer. About 30,000 people in the UK die from lung cancer each year. More than 8 in 10 cases are directly related to smoking.
Chronic obstructive pulmonary disease (COPD). About 25,000 people in the UK die each year from this serious lung disease. More than 8 in 10 of these deaths are directly linked to smoking. People who die of COPD are usually quite unwell for several years before they die.
Heart disease is the biggest killer illness in the UK. About 120,000 people in the UK die each year from heart disease. About 1 in 7 of these deaths are due to smoking.
Pregnancy:
Miscarriage.
Low birth weight. Babies born to women who smoke are on average 200 grams (8 oz) lighter than babies born to comparable non-smoking mothers. Premature and low birth weight babies are more prone to illness and infections.
Stillbirth or death within the first week of life - the risk is increased by about one-third.
Smoking affects other people.
Children
* Are more prone to asthma and ear, nose and chest infections. About 17,000 children under five years old in England and Wales are admitted to hospital each year due to illnesses caused by their parents smoking.
* Have an increased risk of dying from cot death (sudden infant death syndrome).
* On average, do less well at reading and reasoning skills compared to children in smoke-free homes, even at low levels of smoke exposure.
* Are at increased risk of developing chronic obstructive pulmonary disease and cancer as adults.
Passive smoking of adults.
You have an increased risk of lung cancer and heart disease if you are exposed to other people smoking for long periods of time. Tobacco smoke is also an irritant, and can make asthma and other conditions worse.
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