Persistent Cough

Medically Reviewed By William C. Lloyd III, MD, FACS

What is a persistent cough?

Coughing is your body’s defensive reflex that keeps your airways clear of irritating or obstructing substances (e.g., mucus) so 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 people visit their primary care doctor.

Primary care physicians often categorize coughs into acute (lasting less than three weeks), subacute (lasting three to eight weeks), and persistent (lasting eight weeks or longer).

A persistent cough is a symptom of a wide variety of mild to serious diseases, disorders and conditions including infection, inflammation, trauma, malignancy, airway obstruction, and other abnormal processes.

A persistent cough can be due to fairly mild conditions, such as postnasal drip following a cold. A persistent cough in someone who smokes is usually due to smoking and may lead to chronic bronchitis. A persistent cough can also be due to life-threatening diseases including congestive heart failure or tuberculosis. Allergic problems and certain medications can cause cough as well. Some individuals taking angiotensin-converting enzyme inhibitors (ACE inhibitors) experience a persistent dry cough, which ceases with drug discontinuation.

A persistent cough can be a sign of a serious or life-threatening disorder. If you have difficulty breathing, chest pain, rapid heartbeat, swollen legs or ankles, or are coughing up blood or pink, frothy mucus, seek immediate medical care (call 911).  Coughing up blood or pink, frothy mucus is a sign of pulmonary edema, which can lead to respiratory arrest. Any sign of blood is a potentially serious problem.

What other symptoms might occur with a cough?

A persistent cough may occur in conjunction with other symptoms, which vary depending on the underlying disease, disorder or condition. Other symptoms include fever, difficulty breathing, and chest pain. Some symptoms, such as sounds the lungs make while you are breathing, changes in blood pressure, and low blood oxygen levels may only be evident using certain instruments in the doctor’s office or hospital.

Common symptoms that may occur along with a persistent cough

Persistent cough may occur with other symptoms including:

Other symptoms that may occur along with a persistent cough

Persistent cough may occur with less common symptoms including:

Serious symptoms that might indicate a life-threatening condition

In some cases, a persistent cough may occur with other symptoms that might indicate a serious or life-threatening condition that should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, are exhibiting any of these life-threatening symptoms:

What causes a persistent cough?

The most common causes of a persistent cough are asthma, postnasal drip, and gastroesophageal reflux disease (GERD). A persistent cough is not usually due to infection, although there are infectious diseases that are associated with a chronic cough. Less commonly, a persistent cough is due to life-threatening conditions, such as heart failure, pulmonary edema, or lung cancer. There are other possible causes as well, so talk to your medical professional about your symptoms.

Infectious causes of a persistent cough

A persistent cough can be due to certain infections including:

Other causes of a persistent cough

A persistent cough can be due to causes related to the respiratory, digestive and circulatory systems including:

Medications can cause a persistent cough

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

Questions for diagnosing the cause of a persistent cough

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

  • How long have you had the cough?

  • Are you coughing up anything?

  • Have you been sick recently (with the cold or flu)?

  • Do you have any pets?
  • Do you smoke?

  • Is the cough keeping you up at night or interfering with your daily activities?

What are the potential complications of a persistent cough?

A persistent cough can be a sign of an infectious or inflammatory process, many of which can be easily treated. It is important to visit your health care provider when you experience a persistent cough without an obvious cause. Once the underlying cause is diagnosed, following the treatment plan outlined by your doctor can help lower your risk of potential complications associated with a long-lasting cough including:

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  1. Cough.
  2. Cough. Medline Plus, a service of the National Library of Medicine National Institutes of Health.
  3. Domino FJ (Ed.) Five Minute Clinical Consult. Philadelphia: Lippincott Williams & Wilkins, 2013.
  4. Birring SS. Controversies in the evaluation and management of chronic cough. Am J Respir Crit Care Med 2011; 183:708.
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 8
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