Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

Cough

by Rick Alan
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 three weeks
  • Chronic cough—lasts longer than eight weeks
  • Subacute cough—lasts 3-8 weeks
Causes

An acute cough is usually caused by an infection, such as a cold or 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 be exposure to irritants or to anything that can cause chronic cough.

A chronic cough can be caused by many factors. Common examples include:

Risk Factors

The main risk factor for cough is being exposed to irritants, for example:

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

Smoking is a major risk for serious conditions linked to chronic cough, including lung cancer and chronic obstructive pulmonary disease (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.

When Should I Call My Doctor?

Call your doctor if you have:

  • Acute cough that worsens or does not go away on its own
  • Blood in the sputum
  • Chronic cough
  • Cough with wheezing
  • Signs of an infection (eg, fever, chills)
When Should I Call for Medical Help Immediately?

Call for medical help or go to the emergency room right away if your cough is accompanied by:

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

The doctor will ask about your symptoms and medical history, and perform a physical exam.

Acute cough is usually diagnosed by its accompanying symptoms.

During the diagnosis, your doctor will look for symptoms that suggest an underlying cause. Tests may include:

  • Analysis of a sputum sample
  • Blood test to check for infection
  • Bronchoscopy—insertion of a long, thin instrument to view the interior of the airways and collect samples
  • CT scan of the chest—a type of x-ray that uses a computer to create images of structures inside of the chest
  • Chest x-rays —a test that uses radiation to take a picture of structures inside of the chest
  • Pulmonary function tests—to measure lung volumes and air flow rates
  • Skin test for tuberculosis
  • Skin tests if allergies are suspected
Treatment

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

Medication

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

Note: The Food and Drug Administration (FDA) recommends against using OTC cough and cold products to treat infants and young children (less than four years old). Rare but serious side effects have been reported, including death, convulsions, and rapid heart rate.

Lifestyle Changes

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

If you smoke, talk to your doctor about strategies to quit. Smoking impacts your lung function and increases your risk of many diseases.

If you are diagnosed with a cough, follow your doctor's instructions.

Prevention

To help avoid a cough:

  • When working in areas where noxious fumes or airborne substances are present:
    • Be sure the area is properly ventilated.
    • Wear a protective mask or respirator.
  • Be a nonsmoker.
  • Get proper treatment for the underlying condition.

Last reviewed: January 2012 by Peter J. Lucas, MD.

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