Cough

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.

For information about coughs in children, see the topic Coughs, Age 11 and Younger.

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 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 aschronic 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 (postnasal drip) draining down the back of the throat. 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 mean 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.

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