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Chronic Cough Introduction |
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A
cough can arise for a
variety of reasons, for which
the cause must first be
determined. Physiologically
speaking, the cough is a
necessary body function.
It is the body's mechanism of
action for clearing material
from the airway. For example, if
some fluid or small food
particle is aspirated upon
ingestion, cough acts as a
protective mechanism.
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The cough
mechanism is thought to be the
result of cough receptors found in
the nose, sinuses, auditory canals,
nasopharynx, larynx, trachea,
bronchi, pleurae, diaphragm , and
probably, the pericardium and GI tract.
(1) If one or more of the receptors is
stimulated, the resultant cascade
travels through the vagus and
glossopharyngeal nerves to the
medulla, which is located in the brainstem.
This is known as the cough center.
Upon the stimulation
of a given receptor, the cough center is
activated. This causes a reflexive
action of laryngeal, intercostal, and
abdominal muscles; combined with
closure of the glottis and deep
inspiration. Thee processes increase
lung pressure and causes tthe
glottis to forcefully open forcefully.
This is the event
we term cough. This cascade can also
be externally stimulated from
either applied force, or by forced
expiration.
Cough is categorized
into productive and nonproductive
types, which refers to whether
sputum or blood is being expelled. A
chronic cough is defined as a
cough that persists beyond one
month, as coughs may occur as a single or paroxysmal episode.
Troubled breathing (dyspnea),
chest or throat pain, hoarseness, or
weight loss are vital to
understanding the cause of a
chronic cough. The
most common cause of chronic cough
is cigarette smoking. Smokers
cough is referred to as a productive
cough. This production is due
to the expelling of a mucus-like
sputum that appears clear to yellow,
or even brown.
The physical
characteristics of sputum can help
inform the care provider as to the
nature of the disorder. For
example, if there is gritty
material, it may be a condition
known as broncholithiasis.
Another important aspect to consider
is the onset, duration, and
chronology of the cough. A
well educated provider will ask to
examine all attributes of the
patient's history, and will perform
a full physical examination to
determine the nature of the chronic
cough. Laboratory tests and
diagnostic imaging will likely be
performed to rule out conditions
such as bronchogenic carcinoma (a
type of lung cancer) or
tuberculosis.
Other causes of
chronic cough include;
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asthma
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chronic bronchitis
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emphysema
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COPD (chronic
obstructive pulmonary disease)
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hypersensitivity
pneumonitis
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interstitial lung
disease
-
aryngeal tumor
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pulmonary edema
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sarcoidosis
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cystic fibrosis
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bronchiectasis
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chronic lung abcess
-
allergic rhinitis
-
nocardiosis
-
silicosis.
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Learn More About
Chronic Cough |
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