Effects of tobacco and smoking
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.
Immediate effects of smoking
Low to moderate doses
Some of the effects that may be experienced after smoking tobacco include:
- initial stimulation, then reduction in activity of brain and nervous system
- increased alertness and concentration
- feelings of mild euphoria
- feelings of relaxation
- increased blood pressure and heart rate
- decreased blood flow to fingers and toes
- decreased skin temperature
- bad breath
- decreased appetite
- nausea, abdominal cramps and vomiting
- coughing, due to smoke irritation.
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:
- an increase in the unpleasant effects
- feeling faint
- rapid decrease in blood pressure and breathing rate
- respiratory arrest (stopping breathing) and death.
60 mg of nicotine taken orally can be fatal for an adult.
Long-term effects of smoking
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:
- increased risk of stroke and brain damage
- eye cataracts, macular degeneration, yellowing of whites of eyes
- loss of sense of smell and taste
- yellow teeth, tooth decay and bad breath
- cancer of the nose, lip, tongue and mouth
- possible hearing loss
- laryngeal and pharyngeal cancers
- contributes to osteoporosis
- shortness of breath
- chronic bronchitis
- triggering asthma
- heart disease
- blockages in blood supply that can lead to a heart attack
- high blood pressure (hypertension)
- myeloid leukaemia, a cancer that affects bone marrow and organs that make blood
- stomach and bladder cancers
- stomach ulcers
- decreased appetite
- grey appearance
- early wrinkles
- slower healing wounds
- damage to blood vessel walls
- increased likelihood of back pain
- increased susceptibility to infection
- lower fertility and increased risk of miscarriage
- irregular periods
- early menopause
- damaged sperm and reduced sperm
Other effects of tobacco use
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.
Using tobacco with other drugs
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.
Pregnancy and breastfeeding
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.
Tolerance and dependence
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.
For more information, please click on the Alcohol and Drug Foundation’s (previously Australian Drug Foundation) logo below.