Chronic Cough with Uncertain Cause (Adult)

Everyone has had a cough as part of the common cold, flu, or bronchitis. This kind of cough occurs along with an achy feeling, low-grade fever, nasal and sinus congestion, and a scratchy or sore throat. This usually gets better in 2 to 3 weeks. A cough that lasts longer than 3 weeks may be due to other causes. Your healthcare provider may refer to this as a chronic cough.

If your cough does not improve over the next 2 weeks, further testing may be needed. Follow up with your healthcare provider as advised. Cough suppressants may be recommended. Based on your exam today, the exact cause of your cough is not certain. Below are some common causes for persistent cough.

Smoker's cough

Smoker’s cough doesn’t go away. If you continue to smoke, it only gets worse. The cough is from irritation in the air passages. Talk to your healthcare provider about quitting. Medicines or nicotine-replacement products, like gum or the patch, may make quitting easier.

Postnasal drip

A cough that is worse at night may be due to postnasal drip. Excess mucus in the nose drains from the back of your nose to your throat. This triggers the cough reflex. Postnasal drip may be due to a sinus infection or allergy. Common allergens include dust, tobacco smoke (both inhaled and secondhand smoke), environmental pollutants, pollen, mold, pets, cleaning agents, room deodorizers, and chemical fumes. Over-the-counter antihistamines or decongestants may be helpful for allergies. A sinus infection may require antibiotic treatment. See your healthcare provider if symptoms continue.

Front view of man showing respiratory and upper digestive anatomy.


Certain prescribed medicines can cause a chronic cough in some people:

  • ACE inhibitors for high blood pressure. These include enalapril, lisinopril, and others.

  • Beta-blockers for high blood pressure and other conditions. These include propranolol, metoprolol, and others.

Let your healthcare provider know if you are taking any of these. The chronic cough may mean your medicine needs to be changed.


Cough may be the only sign of mild asthma. You may have tests to find out if asthma is causing your cough. You may also take asthma medicine on a trial basis.

Acid reflux (heartburn, GERD)

The esophagus is the tube that carries food from the mouth to the stomach. A valve at its lower end prevents stomach acids from flowing upward. If this valve does not work properly, acid from the stomach enters the esophagus. This may cause a burning pain in the upper abdomen or lower chest, belching, or cough. Symptoms are often worse when lying flat. Avoid eating or drinking before bedtime. Try using extra pillows to raise your upper body, or place 4-inch blocks under the head of your bed. You may try an over-the-counter (OTC) antacid or an acid-blocking medicine such as cimetidine, or omeprazole. Stronger medicines for this condition can be prescribed by your healthcare provider. Ask your healthcare provider which OTC medicine to use. Depending on your current medicines, some OTC medicines may cause drug interactions and should be avoided.

Follow-up care

Follow up with your healthcare provider, or as advised, if your cough doesn't improve. Further testing may be needed.

Note: If an X-ray was taken, you'll be told of any new findings that may affect your care.

When to get medical advice

Call your healthcare provider right away if any of these occur:

  • Mild wheezing or trouble breathing

  • Fever of 100.4ºF (38ºC) or higher, or as advised by your provider

  • Unexpected weight loss

  • Coughing up large amounts of colored sputum or blood-tinged sputum

  • Night sweats (sheets and pajamas get soaking wet)

Call 911

Call 911 if any of these occur:

  • Coughing up blood

  • Moderate to severe trouble breathing or wheezing

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