Understanding Nicotine Addiction and Cravings

Nicotine is a poisonous insecticide chemical produced by the tobacco plant to protect it from being eaten by insects. It constricts the blood vessels particularly the coronary arteries and raises blood pressure levels. It causes high levels of pressure on the heart, increases heart rate, and reduces oxygen levels reaching the heart leading to irregular heart rhythms.

Once we receive nicotine in our blood, it also reaches our brain where it directly and indirectly takes control of many of our neuro chemicals, in particular dopamine.

What is Dopamine?

Dopamine is a natural chemical transmitter in the brain. Its many functions includes the regulation of moods. The brain cells release dopamine when a person is experiencing something pleasurable such as enjoying a meal, sports, meditation etc. This dopamine production can lead to regulating emotions and often people will repeat actions when they receive the good feelings of dopamine.

Dopamine uses a “desire” sensation to get our attention when the body needs something. For example, when we need food our dopamine pathways are being stimulated until we eat food and the stomach peptides tell the brain that we are full and satisfied.

How nicotine affects dopamine?

Research has shown that nicotine increases levels of dopamine in the rewards circuits of our brain. Nicotine effects our natural state of neuro chemical transmitters in that it takes over the production of dopamine and with continual use smokers are falsely led to believe that needing more nicotine is essential for survival and without it they couldn’t survive.

This is one of the major reasons why it is so difficult to overcome nicotine addiction. The brain dopamine pathway continuously sends false messages that nicotine is an important part of life. The dopamine pathway memories of a smoker are so vivid that it is difficult for them to remember the pre-smoking natural state of calmness.

This reaction is similar to that seen in other drugs of abuse and is thought to be the underlying reason for the pleasurable sensations experienced by smokers.  For many smokers of cigarettes, long term brain changes induced by continued nicotine exposure result in addiction.

Within ten seconds of the very first puff of the first cigarette up to 50% of the brains dopamine pathways are taken over by nicotine.  With the completion of one cigarette almost all dopamine pathways are taken over by nicotine.

How nicotine activates the flight or fight response

In addition to taking over our dopamine production, nicotine also activates the body’s fight or flight response. This leads to stimulating the adrenal glands and putting the body in a constant state of high alert and high anxiety.  Once it becomes a learned way of being, a huge strain is put on the body and the organs including the lungs, kidneys, heart, digestive system and the respiratory system.

Other poisonous chemicals in cigarettes

Carbon Monoxide: This chemical is also produced by car exhausts.  It depletes the body of its oxygen. This then flows on to a lower oxygen level in the heart and the blood stream affecting body tissues, bodily organs as well as brain functioning.

Tars: These are poisonous chemicals that are left in the lungs from each cigarette. The leading cause of certain cancers.

Phenol: These stunt the cilia which line the bronchial tubes leading to destruction of lung tissue.

Carcinogens: Such as Hydrogen Cyanide which is used in gas chambers in the US and Endrin and DDT which are used as pesticides.

Other toxic metals such as arsenic and nickel have also been found in cigarette smoke.

What one cigarette does to your body

  • Reduces lung capacity, narrows bronchial tubes
  • Constricts blood vessels, particularly coronary arteries
  • Reduces of oxygen levels.
  • Creates irregular heart rhythms
  • Increases pulse rate and blood pressure, causes heart to work harder
  • Within 7 seconds it affects the nervous system and increases muscle tension


National Institute of Health
Addiction Recovery Centre
The Brain that Changes itself, Norman Doidge MD
Freedom from Nicotine – The Journey Home, John R Polito