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smoking and health There are no health benefits
and numerous health risks from cigarette smoking.
In the 1940s few people, including doctors, recog-
nized the magnitude of health risks associated with
cigarette smoking. But 20 years later cigarette
smoking was a known and publicly identified risk
factor for numerous health conditions and the pri-
mary cause of HEARTdisease and LUNG CANCER. In the
1965 cigarette smoking in the United States peaked
with about 45 percent of American adults being
smokers; by the early 2000s, only 23 percent of
American adults smoked. However, that 23 percent
represents 48 million people who have significantly
increased risk for CARDIOVASCULAR DISEASE (CVD),
chronic lung disease, and cancer. Cigarette smoking
remains the leading cause of preventable disease in
the United States.

PACK YEARS AND DISEASE RISK

One method of representing the amount of ciga-

rette smoke exposure an individual has had is

the “pack year.” This calculation expresses the

number of packs of cigarettes a person smokes

each day times the number of years the person

has smoked. A person who has smoked for 10

pack years may have smoked half a pack a day

for 20 years, one pack a day for 10 years, or two

packs a day for five years. The higher the number

of pack years, the greater exposure and more sig-

nificant the risk of pulmonary and cardiovascular

disease.

How Smoking Affects the Body and Health
Cigarette smoking affects every cell in the body
beginning within seconds of the first inhalation
from a cigarette. NICOTINEcontracts BLOODvessels,
increases HEART RATE, raises BLOOD PRESSURE, and
activates neurotransmitters in the BRAINthat result

in CENTRAL NERVOUS SYSTEMstimulation to produce

a combined sense of exhilaration and alertness.

With each inhalation of cigarette smoke, tar

makes its way to the delicate alveoli deep within

the LUNGS, clogging them and preventing them

from exchanging oxygen. Other chemicals in the

smoke irritate the bronchi, causing an increase in

mucus production and narrowing of the bronchial

openings. Carbon monoxide beats out oxygen to

bind with HEMOGLOBINin the red blood cells (ery-

throcytes), cutting by up to 60 percent the

amount of oxygen each breath carries into the

blood circulation. The combined effects of these

actions and the chemicals that enter the blood-

stream affect cellular METABOLISM in countless

ways. Dozens of these chemicals are carcinogenic;

they cause cells within the body to develop into

cancers. Some of the effects linger for hours after

the cigarette and compound with further smoking.

Cigarette smoking and CVD The leading health

consequence of cigarette smoking is CVD.

Repeated exposure to nicotine causes permanent

changes in the cells that form the lining of the

arteries, making the arteries vulnerable to ATHERO-

SCLEROTIC PLAQUEdeposits and, over time, ATHERO-

SCLEROSIS, CORONARY ARTERY DISEASE (CAD), and

PERIPHERAL VASCULAR DISEASE(PVD). Persistent nico-

tine exposure also causes the arteries to stiffen and

lose FLEXIBILITY. These changes lead to HYPERTENSION

(high blood pressure) and increased risk for HEART

ATTACK and STROKE. The strain on the heart can

eventually cause HEART FAILURE.

Cigarette smoking and cancer The primary

form of cancer associated with cigarette smoking is

lung cancer. However, cigarette smoking increases

the risk for various forms of cancer, including oral

cancer, laryngeal cancer,ESOPHAGEAL CANCER, PAN-

CREATIC CANCER, BLADDER CANCER, PROSTATE CANCER,

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