The effects of any drug (including tobacco) vary from person to person. How tobacco affects a person depends on many things including their size, weight and health, also whether the person is used to taking it. The effects of tobacco, as with any drug, also depend on the amount taken.
In Australia, tobacco use is responsible for approximately 15,000 deaths each year. In 2004–2005 approximately three-quarters of a million hospital bed-days were a result of tobacco use. (Collins & Lapsley, 2008)
There is no safe level of tobacco use. Use of any drug always carries some risk—even medications can produce unwanted side effects. It is important to be careful when taking any type of drug.
Some of the effects that may be experienced after smoking tobacco include:
A high dose of nicotine can cause a person to overdose. This means that a person has taken more nicotine than their body can cope with. The effects of very large doses can include:
60 mg of nicotine taken orally can be fatal for an adult.
Tar in cigarettes coats the lungs and can cause lung and throat cancer in smokers. It is also responsible for the yellow–brown staining on smokers’ fingers and teeth.
Carbon monoxide in cigarettes reduces the amount of oxygen available to the muscles, brain and blood. This means the whole body—especially the heart—must work harder. Over time this causes airways to narrow and blood pressure to rise, which can lead to heart attack and stroke.
High levels of CO, together with nicotine, increase the risk of heart disease, hardening of the arteries and other circulatory problems.
Some of the long-term effects of smoking (Quit Victoria, 2010) that may be experienced include:
Passive smoking occurs when a person who is not smoking breathes in the smoke from people who are smoking. Passive smoking can irritate the eyes and nose and cause a number of health problems such as heart disease and lung cancer. Tobacco smoke is especially harmful to babies and young children.
Nicotine can affect the way the body processes many different drugs. This can affect how these drugs work. For example, nicotine can decrease the effectiveness of benzodiazepines. Smoking while taking the contraceptive pill increases the risk of blood clots forming.
Check with your doctor or other health professional whether nicotine might affect any medications you are taking.
Read about the effects of tobacco use on pregnancy and breastfeeding.
Many drugs can cross the placenta and affect an unborn child.
In general, using drugs when pregnant can increase the chances of going into labour early. This can mean that babies are born below the normal birth weight.
If a mother uses drugs while breastfeeding, they may be present in her milk, and could affect the baby.
Check with your health professional if you are taking or planning to take any drugs during pregnancy, or while breastfeeding.
People who use tobacco regularly tend to develop a tolerance to the effects of nicotine. This means they need to smoke more tobacco to get the same effect.
They may become dependent on nicotine. Dependence can be psychological, physical, or both. People who are dependent on nicotine find that using the drug becomes far more important than other activities in their life. They crave the drug and will find it very difficult to stop using it.
People who are psychologically dependent on nicotine may find they feel an urge to smoke when they are in specific surroundings or socialising with friends.
Physical dependence occurs when a person’s body adapts to the nicotine and gets used to functioning with the nicotine present.
Last Reviewed: 27 April 2012