How is chronic cough diagnosed?

Diagnosing the cause of chronic cough can be difficult. This is because many patients have more than one cause of their cough. Therefore, many types of tests are used to diagnose the causes. The other symptoms will help determine which tests are needed.

  • Lab tests: These tests help determine if bacteria are present (a sign of an infection) and are causing the cough.
  • Lung function studies: These tests measure your breathing pattern – from inhaling to exhaling.
  • Imaging tests: These tests include X-rays, CT and MRI scans, ultrasound and nuclear testing. X-rays reveal the more common reasons for chronic cough, such as a build-up of fluids in the areas that help breathing, as well as lung diseases and lung cancer. All of the other imaging tests provide more detailed views of areas of the body that affect breathing.
  • Scoping studies: In these tests, a scope is passed into the areas that might reveal the cause of chronic cough. For example, a scope can be passed:
    • Up through the nostrils to look for signs of infection or blockages in the nasal passages.
    • Through the nose into the voice box area to look for signs of acid reflux, post-nasal drip, and abnormalities in the upper airway.
    • Down the esophagus and into the stomach to measure the level of acid, which would help determine if acid reflux is the cause of chronic cough.
    • Down the windpipe and into the bronchial tubes to look for blockages and signs of infections in the lung.

Last reviewed by a Cleveland Clinic medical professional on 03/09/2016.


  • National Heart, Lung, and Blood Institute. What Is Cough? Accessed 3/11/2016.
  • Chung KF, Widdicombe JG. Causes and Treatment of Acute and Chronic Cough. In: Mason, ed. Murray and Nadel's Textbook of Respiratory Medicine, 5th ed.; Philadelphia, Pa: Saunders Elsevier; 2010: Chapter 29.
  • Dweik RA. Cough – Etiology. In: Carey, WD, ed. Cleveland Clinic: Current Clinical Medicine 2010.2nd ed.; Philadelphia, Pa: Saunders Elsevier; 2010: section 12.
  • Kelkar P, Weldon D. Approach to the Patient with Chronic Cough. In: Adkinson FM, et al. Middleton's Allergy: Principles and Practice. 7th ed.; St. Louis: Mosby; 2008: Chapter 79.

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