Definition

A cough is a sudden burst of air from the lungs. It can help to clear mucus or foreign items from the airways.

There are different types of cough:

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

Causes

Acute coughs are often caused by infections, such as colds or the flu. Other causes may be:

• Exposure to an irritant or allergen
• Inhaling a foreign object
• Acute bronchitis
• Pneumonia

A subacute cough often follows a respiratory infection or irritation.

A chronic cough has many causes. Common ones are:

• Chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis or emphysema
• Asthma
• Gastroesophageal reflux disease (GERD)
• Postnasal drip, which may be due to:
  • Inhaling irritants often
  • Sinus inflammation
  • Allergies
• Bronchiectasis
• Certain medicines, such as angiotensin-converting enzyme (ACE) inhibitors

Alveoli (Air Sacs) of Lung Copyright © Nucleus Medical Media, Inc.

Risk Factors

Things that raise the risk of coughs are:

• Infections
• Smoking or being near smoke
• Harmful fumes
• Allergens, such as pollen and dust
• Air pollution

Symptoms

Coughs can have fluid or be dry. A cough may be worse when waking up or when lying down.

Diagnosis

The doctor will ask about your symptoms and health history. A physical exam will be done.

An acute cough is usually diagnosed by symptoms that occur with it.

If coughing is severe or long lasting, tests may be done to look for the cause. Tests may be:

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

Images may be taken to look at the lungs and other structures. They may include:

• Chest x-ray
• CT scan

Other tests may include:

• Bronchoscopy—a lighted tube put in the lungs to view the area and/or take a tissue sample
• Pulmonary function tests—to check how well the lungs work

Treatment

The goal is to treat the underlying cause of a cough. It is also to ease symptoms and prevent further problems. Coughs due to infections often go away on their own. Other coughs may need treatment. Some people may be referred to a specialist.

Depending on the cause of the cough, some options may be:

• Lifestyle changes, such as:
  • Staying away from irritants such as smoke, dust, or fumes
  • Strategies to quit smoking
  • Using a cool mist humidifier—to loosen mucus
• Over-the-counter or prescription medicines, such as:
  • Cough and cold medicines
  • Corticosteroids by mouth, inhalers, or nasal sprays—to reduce inflammation
  • Bronchodilators—to open the airways
  • Acid reducers—for people with acid reflux

Prevention

Things that may help reduce the risk of a long term cough are:

• Not smoking
• Using masks and ventilation—when near harmful fumes or airborne substances