What causes a cough?

A cough has many causes, the most common of which is an upper airway infection, such as a common cold. A persistent cough can be due to whooping cough (pertussis) or a sign of a chronic lung condition, such as emphysema or asthma. Some individuals taking angiotensin-converting enzyme inhibitors (ACE inhibitors) experience a persistent dry cough, which ceases with drug discontinuation. Whooping cough is uncommon in infants due to vaccination, but it is surprisingly common in adults because the vaccination becomes less effective over time.

Very serious and life-threatening conditions that cause coughing include congestive heart failure, pulmonary edema, and lung cancer. Other possible causes include allergies, pneumonia, and bronchitis. Because there are so many different possibilities, some of which are life threatening, it is important to contact your doctor to discuss your symptoms and answer your questions.

Infectious causes of cough

Cough is a symptom of various viral and bacterial infections including:

  • Acute bronchitis

  • Common cold (viral respiratory infection)

  • Croup (viral illness that is common in young children)

  • Influenza (flu)

  • Pneumonia

  • Tuberculosis (serious infection affecting the lungs and other organs)

  • Whooping cough (pertussis)

Other causes of cough

Other causes of cough include:

  • Acid reflux or gastroesophageal reflux disease (GERD)

  • Airway irritation such as from air pollution

  • Asthma and allergies

  • Chronic obstructive pulmonary disease (COPD, includes emphysema and chronic bronchitis)

  • Congestive heart failure (deterioration of the heart’s ability to pump blood)

  • Foreign body (airway obstruction)

  • Lung cancer

  • Postinfectious cough
  • Postnasal drip from sinusitis or upper respiratory infection such as the common cold

  • Pulmonary edema

  • Pulmonary embolism

  • Smoking

  • Tumor of the larynx

Medications can cause a cough

Certain medications that can cause a cough include ACE inhibitors (including captopril), which is used to control high blood pressure.

Questions for diagnosing the cause of a cough

To aid in diagnosing the cause of your cough, your doctor or licensed health care practitioner will ask you questions related to your symptoms including:

  • How long have you had the cough?

  • Are you coughing up anything (including blood)?

  • Are you breathing through your mouth (instead of your nose)?

  • Is your cough keeping you up at night?

  • Do you have a fever?

What are the potential complications of a cough?

A cough can be a sign of an infectious or inflammatory process, many of which can be easily treated. It is important to contact your health care provider when you experience a cough without an obvious cause or if your cough is persistent, recurrent, or causes you concern. Once the underlying cause is diagnosed, following the treatment you and your doctor design specifically for you can help lower your risk of potential complications including:

  • Dehydration if cough occurs with diarrhea or vomiting

  • Dehydration due to reduced fluid intake

  • Difficulty sleeping

  • Fainting spells from acute cough attack

  • Fatigue

  • Vomiting


  1. Cough. FamilyDoctor.org. http://familydoctor.org/familydoctor/en/health-tools/search-by-symptom/cough.html.
  2. Cough. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/cough.html.
  3. Tierney LM Jr., Saint S, Whooley MA (Eds.) Current Essentials of Medicine (4th ed.). New York: McGraw-Hill, 2011.

What is a cough?

A cough is your body’s defensive reflex that functions to keep your airways clear of irritating or obstructing substances so that you can breathe effectively. A cough can be dry or it can be productive, meaning that you are coughing up mucus (also known as phlegm or sputum). A cough is one of the most common reasons why people visit their primary care doctor.

A cough is a symptom... Read more about coughintroduction


What other symptoms might occur with a cough?

A cough often occurs in conjunction with other symptoms, which vary depending on the underlying disease, disorder or condition. Other symptoms include fever, shortness of breath, and chest pain. Some symptoms, such as sounds the lungs make while you’re breathing, changes in blood pressure, and low blood oxygen lev... Read more about coughsymptoms

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Aug 9, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Lungs, Breathing and Respiration

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