Coughing is the body's way of removing foreign material or mucus
from the lungs and upper airway passages
or of reacting to an
irritated airway. Coughs have distinctive traits you can learn to recognize. A
cough is only a symptom, not a disease, and often the importance of your cough
can be determined only when other symptoms are evaluated.
Productive coughs
A productive cough produces
phlegm or mucus (sputum). The mucus may have drained down the back of the
throat from the nose or sinuses (postnasal drainage) or may have come up
from the lungs. A productive cough generally should not be suppressed; it
clears mucus from the lungs. There are many causes of a productive cough, such
as:
- Viral illnesses. It is normal to have a productive cough when
you have a common cold. Coughing is often triggered by mucus that drains down
the back of the throat.
- Infections. An infection of the lungs or upper airway passages
can cause a cough. A productive cough may be a symptom of
pneumonia,
bronchitis,
sinusitis, or
tuberculosis.
- Chronic lung disease. A productive cough could be a sign that a
disease such as
chronic obstructive pulmonary disease (COPD) is
getting worse or that you have an infection.
- Stomach acid backing up into the
esophagus. This type of coughing may be a symptom of
gastroesophageal reflux disease (GERD) and may awaken
you from sleep.
- Nasal discharge draining down the back of the throat (postnasal
drip syndrome). This can cause a productive cough or the feeling that you
constantly need to clear your throat. Experts disagree about whether a
postnasal drip or the viral illness that caused it is responsible for the
cough.
- Smoking or other tobacco use. Productive coughs in a person who
smokes or uses other forms of tobacco is often a sign of lung damage or
irritation of the throat or esophagus.
Nonproductive coughs
A nonproductive cough is dry
and does not produce sputum. A dry, hacking cough may develop toward the end of
a cold or after exposure to an irritant, such as dust or smoke. There are many
causes of a nonproductive cough, such as:
- Viral illnesses. After a common cold, a dry cough may last
several weeks longer than other symptoms and often gets worse at night.
- Bronchospasm. A nonproductive cough, particularly at night, may
indicate spasms in the bronchial tubes (bronchospasm) caused by
irritation.
- Allergies. Frequent sneezing is also a common symptom of
allergic rhinitis.
- Medicines called ACE inhibitors that are used to control
high blood pressure. Examples of ACE inhibitors
include captopril (Capoten), enalapril maleate (Vasotec), and lisinopril
(Prinivil, Zestril, or Zestoretic).
- Exposure to dust, fumes, and chemicals in the work
environment.
- Asthma. A chronic dry cough may be a sign of mild
asthma. Other symptoms may include wheezing, shortness of breath, or a feeling
of tightness in the chest. For more information, see the topic
Asthma in Teens and Adults.
- Blockage of the airway by an inhaled object, such as food or a
pill. For more information, see the topic
Swallowed Objects.
Coughs in children
Children may develop coughs
from diseases or causes that usually do not affect adults, such as:
Many coughs are caused by a viral illness. Antibiotics
are not used to treat viral illnesses and do not alter the course of viral
infections. Unnecessary use of an antibiotic exposes you to the risks of an
allergic reaction and antibiotic side effects, such as
nausea, vomiting, diarrhea, rashes, and yeast infections. Antibiotics also may
kill beneficial bacteria and encourage the development of dangerous
antibiotic-resistant bacteria.
A careful
evaluation of your health may help you identify other symptoms. Remember, a
cough is only a symptom, not a disease, and often the importance of your cough
can only be determined when other symptoms are evaluated. Coughs occur with
bacterial and viral respiratory infections. If you
have other symptoms, such as a sore throat, sinus pressure, or ear pain, see
the Related Information section.
Review the Emergencies and Check
Your Symptoms sections to determine if and when you need to see a
doctor.