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How Is the Cause of Cough Diagnosed?

Your doctor will diagnose the cause of your cough based on your medical history, a physical exam, and test results.

Medical History

Your doctor will likely ask questions about your cough. He or she may ask how long you've had it, whether you're coughing anything up (such as mucus, a slimy substance), and how much you cough.

Your doctor also may ask:

  • About your medical history, including whether you have allergies, asthma, or other medical conditions.
  • Whether you have heartburn or a sour taste in your mouth. These may be signs of gastroesophageal reflux disease (GERD).
  • Whether you've recently had a cold or the flu.
  • Whether you smoke or spend time around others who smoke.
  • Whether you've been around air pollution, a lot of dust, or fumes.

Physical Exam

To check for signs of problems related to cough, your doctor will use a stethoscope to listen to your lungs. He or she will listen for wheezing (a whistling or squeaky sound when you breathe) or other abnormal sounds.

Diagnostic Tests

Your doctor may recommend tests based on the results of your medical history and physical exam. For example, if you have symptoms of GERD, your doctor may recommend a pH probe. This test measures the acid level of the fluid in your throat.

Other tests may include:

  • An exam of the mucus from your nose or throat. This test can show whether you have a bacterial infection.
  • A chest x ray. A chest x ray takes a picture of your heart and lungs. This test can help diagnose conditions such as pneumonia and lung cancer.
  • Lung function tests. These tests measure how much air you can breathe in and out, how fast you can breathe air out, and how well your lungs deliver oxygen to your blood. Lung function tests can help diagnose asthma and other conditions.
  • An x ray of the sinuses. This test can help diagnose a sinus infection.
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Cough Clinical Trials

Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway for Cough, visit

October 01, 2010 Last Updated Icon

The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.