A cough is a sudden expulsion of air from the lungs. Its purpose is usually to clear secretions and inhaled foreign substances from the lungs and respiratory tract.

There are different types of cough:

  • Acute cough—lasts for less than 3 weeks
  • Subacute cough—lasts 3-8 weeks
  • Chronic cough—lasts longer than 8 weeks

Causes    TOP

An acute cough is usually caused by an infection, such as a cold or the flu. In some cases, an acute cough can be the sign of other conditions, such as:

Subacute cough is often a cough that follows a respiratory infection. It can also be caused by exposure to irritants or to anything that can cause chronic cough.

A chronic cough has many causes. Common examples include:

Alveoli (Air Sacs) of Lung

Chronic Bronchitis
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Risk Factors    TOP

Factors that may increase your risk of developing a cough include:

  • Infection
  • Tobacco smoke
  • Harmful fumes
  • Allergens, such as pollen and dust
  • Smog and other environmental pollutants

Smoking is a major risk factor for serious conditions linked to chronic cough, including lung cancer and COPD.

Symptoms    TOP

A cough can be a symptom of an underlying condition.

Coughs can be productive or dry. You may find that your cough is worse when waking up and during the night while lying down.

When Should I Call My Doctor?

Call your doctor if you have:

  • Acute cough that worsens or does not go away on its own
  • Cough lasting more than 8 weeks
  • Signs of an infection, including fever and chills
  • Cough with wheezing
  • Blood in the sputum

When Should I Call for Medical Help Immediately?

Call for medical help or go to the emergency room right away if you have cough with:

  • Pink or frothy sputum
  • Trouble breathing
  • Chest pain
  • Rapid heartbeat
  • Swelling in the legs

Diagnosis    TOP

You will be asked about your symptoms and medical history. A physical exam will be done.

Acute cough is usually diagnosed by its accompanying symptoms.

Your bodily fluids may be tested. This can be done with:

  • Blood tests
  • Skin tests
  • Analysis of a sputum sample

Images may be taken of your bodily structures. This can be done with:

Your lung function and capacity may be tested. This can be done with pulmonary function tests.

Treatment    TOP

The best treatment for a cough is to treat the underlying condition.


There are many over-the-counter (OTC) cough and cold products available. These include decongestants, expectorants, antihistamines, and antitussives.

Note: Cough and cold medications should not be used in children under 2 years old, and they are not recommended in children under 4 years old. The US Food and Drug Administration has not completed its review regarding the safety of over-the-counter cough and cold medications in children ages 2-11 years. Rare, but serious side effects have been reported.

Lifestyle Changes

Consider putting a steam vaporizer or cool-mist humidifier in your room. This type of moisture therapy may help to make secretions looser and easier to cough up.

Prevention    TOP

To reduce your chances of developing a cough:

  • If you smoke, talk to your doctor about strategies to quit. Smoking affects your lung function and increases your risk of many diseases.
  • Get proper treatment for the underlying condition.
  • When working in areas where harmful fumes or airborne substances are present:
    • Be sure the area is properly ventilated.
    • Wear a protective mask or respirator.


American Lung Association
Family Doctor—American Academy of Family Physicians


The Lung Association


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Public health advisory: Nonprescription cough and cold medicine use in children—FDA recommends that over-the-counter (OTC) cough and cold products not be used for infants and children under 2 years of age. US Food and Drug Administration website. Available at: Updated August 20, 2013. Accessed September 17, 2014.
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Last reviewed August 2015 by David Horn, MD
Last Updated: 9/17/2014

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