• Thrombosis. Thrombosis is a process that results in the formation of a clot inside a blood vessel.
Normally, clots form inside blood vessels to stop bleeding, when vessels have been injured.
However, components of tobacco smoke result in dangerously increased rates of clot formation.
Smokers have elevated levels of thrombin, an enzyme that causes the blood to clot, after fasting, as
well as a spike immediately after smoking.26 This process may result in blockage of blood vessels,
stopping blood flow to vital organs. In addition, thrombosis especially occurs around sites of plaque
formation (above). Because of this abnormal tendency to clot, smokers with less severe heart
disease, have more heart attacks than nonsmokers.27 In addition, sudden death is four times more
likely to occur in young male cigarette smokers than in nonsmokers.28
• Constricts blood vessels. It has been shown that smoking, even light smoking, causes the body’s
blood vessels to constrict (vasoconstriction). Smoking does this by decreasing the nitric oxide (NO2),
which dilates blood vessels, and increasing the endothelin-1 (ET-1), which causes constriction of
blood vessels. The net effect is constriction of blood vessels right after smoking and transient
reduction in blood supply. Vasoconstriction may have immediate complications for certain persons,
particularly individuals whose blood vessels are already narrowed by plaques (atherosclerosis), or
partial blood clots, or individuals who are in a hyper-coagulable state (i.e. have sickle cell disease).
These individuals will be at increased risk of stroke or heart attack.29
• Increases heart rate. Heart rate is a measure of how fast your heart is pumping blood around your
body. Young adult smokers have a resting heart rate of two to three beats per minute faster than the
resting heart rate of young adult nonsmokers.30 Nicotine consumption increases a resting heart rate,
as soon as 30 minutes after puffing; and the higher the nicotine consumption (through deep inhalation
or increased number of cigarettes) the higher the heart rate.31 Smokers’ hearts have to work harder
than nonsmokers’ hearts. A heart that is working harder is a heart that can tire-out faster and may
result in an early heart attack or stroke.
• Increases blood pressure. Blood pressure is a measure of tension upon the walls of arteries by
blood. It is reported as a fraction, systolic over diastolic pressure. Systolic blood pressure is the
highest arterial pressure reached during contraction of the heart. Diastolic blood pressure is the
lowest pressure, found during the heart’s relaxation phase. Nicotine consumption increases blood
pressure.32 Older male smokers have been found to have higher systolic blood pressure than
nonsmoking men do.33 Higher blood pressure requires that the heart pump harder in order to
overcome the opposing pressure in the arteries. This increased work, much like that related to
increased heart rate, can wear out a heart faster. The higher pressure can also cause organ damage
where blood is filtered, such as in the kidneys.34
Immediate and Rapid Effects on the Gastrointestinal System
The gastrointestinal system is responsible for digesting food, absorbing nutrients, and dispensing of
waste products. It includes the mouth, esophagus, stomach, small and large intestines, and the anus.
These continuous parts are all easily affected by tobacco smoke.
• Gastroesophageal Reflux Disease. This disease includes symptoms of heartburn and acid
regurgitation from the stomach. Normally the body prevents these occurrences by secreting a base
to counteract digestive acids and by keeping the pathway between the esophagus (the tube between
the mouth and stomach) and stomach tightly closed; except when the stomach is accepting food from
above. The base smokers’ bodies secrete is less neutralizing than nonsmokers and thus allows
digestive acids a longer period of time to irritate the esophagus.35 Smokers also have an intermittent
loosening of the muscle separating the esophagus and stomach, increasing the chance of stomach
acid rising up to damage the esophagus.36 These immediate changes in base secretion and
esophagus/stomach communication cause painful heartburn and result in an increased risk of longterm
inflammation and dysfunction of the esophagus and stomach.37 Smoking also increases reflux
of stomach contents into the esophagus and pharynx.38 Occurring regularly over time, this reflux may cause ulcerations of the lower esophagus, called Barrett’s esophagus, to develop.39 Barrett’s
esophagus may develop into esophageal cancer, which has a poor prognosis in most patients.