Definition

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

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:

• Exposure to an irritant or an allergen
• Aspiration of a foreign body
• Acute bronchitis
• Pneumonia

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:

• Chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis or emphysema
• Asthma
• Acid reflux from the stomach into the esophagus—gastroesophageal reflux disease (GERD)
• Postnasal drip, which may be due to:
  • Repeated inhalation of environmental irritants
  • Sinus inflammation
  • Allergies
• Bronchiectasis
• Certain medications, such as ACE inhibitors

Risk Factors

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

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.

Diagnosis

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:

• X-ray
• CT scan
• Bronchoscopy

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

Treatment

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

Prevention

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.

Family Doctor—American Academy of Family Physicians http://www.familydoctor.org

The Lung Association http://www.lung.ca

Cough. American Academy of Family Physicians Family Doctor website. Available at:
http://familydoctor.org/familydoctor/en/health-tools/search-by-symptom/cough.html
Accessed September 17, 2014.

Coughlin L. Cough: Diagnosis and management. Am Fam Physician. 2007;75(4):567-575.

1/30/2008 DynaMed’s Systematic Literature Surveillance
http://www.ebscohost.com/dynamed:
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: http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm051137.htm. Updated August 20, 2013. Accessed September 17, 2014.

1/30/2008 DynaMed’s Systematic Literature Surveillance
http://www.ebscohost.com/dynamed:
Paul IM, Beiler J, McMonagle A, Shaffer ML, Duda L, Berlin CM Jr. Effect of honey, dextromethorphan, and no treatment on nocturnal cough and sleep quality for coughing children and their parents. Arch Pediatr Adolesc Med. 2007;161(6):1149-1153.

11/12/2010 DynaMed’s Systematic Literature Surveillance
http://www.ebscohost.com/dynamed:
Smith S, Schroeder K, Fahey T. Over-the-counter (OTC) medications for acute cough in children and adults in ambulatory settings. Cochrane Database Syst Rev. 2010;(9):CD001831.