Your doctor will ask about your medical history and perform a physical exam. Your doctor may also order tests to look for the cause of your chronic cough.
However, many doctors opt to start treatment for one of the common causes of chronic cough rather than ordering expensive tests. If the treatment doesn't work, however, you may undergo testing for less common causes.
- X-rays. Although a routine chest X-ray won't reveal the most common reasons for a cough — postnasal drip, acid reflux or asthma — it may be used to check for lung cancer, pneumonia and other lung diseases. An X-ray of your sinuses may reveal evidence of a sinus infection.
- Computerized tomography (CT) scans. CT scans also may be used to check your lungs for conditions that may produce cough or your sinus cavities for pockets of infection.
Lung function tests
These simple, noninvasive tests are used to diagnose asthma and COPD. They measure how much air your lungs can hold and how fast you can exhale.
Your doctor may request an asthma challenge test, which checks how well you can breathe before and after inhaling the drug methacholine (Provocholine).
If the mucus that you cough up is colored, your doctor may want to test a sample of it for bacteria.
If your doctor isn't able to find an explanation for your cough, special scope tests may be considered to look for possible causes.
These tests use a thin, flexible tube equipped with a light and camera. With a bronchoscope, your doctor can look at your lungs and air passages. A biopsy can also be taken from the inside lining of your airway (mucosa) to look for abnormalities.
With a rhinoscope, your doctor can view your nasal passages to look for upper airway causes of cough.
A chest X-ray and spirometry, at a minimum, are typically ordered to find the cause of a chronic cough in a child.
Aug. 22, 2017
- Cough. National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/cough/. Accessed March 2, 2016.
- Bope ET, et al. The respiratory system. In: Conn's Current Therapy 2016. Philadelphia, Pa.: Saunders Elsevier; 2016. http://www.clinicalkey.com. Accessed March 2, 2016.
- Benich JJ, et al. Evaluation of the patient with chronic cough. American Academy of Family Physicians. www.aafp.org/afp. Accessed March 2, 2016.
- Silvestri RC, et al. Evaluation of subacute and chronic cough in adults. http://www.uptodate.com/home. Accessed March 2, 2016.
- Weinberger SE, et al. Treatment of subacute and chronic cough in adults. http://www.uptodate.com/home. Accessed March 9, 2016.
- Chang AB, et al. Cough in the pediatric population. Otolaryngology Clinics of North America. 2010;43:181.
- Morice AH, et al. Recommendations for the management of cough in adults. Thorax. 2006;61(supp):1.
- AskMayoExpert. Chronic cough. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2015.
- An important FDA reminder for parents: Do not give infants cough and cold products designed for older children. U.S. Food and Drug Administration. http://www.fda.gov/Drugs/ResourcesForYou/SpecialFeatures/ucm263948.htm. Accessed March 8, 2016.
- Islam S. Flexible bronchoscopy: Indications and contraindications. http://www.uptodate.com/home. Accessed Jan. 20, 2016.
- Gibson P, et al. Treatment of unexplained chronic cough. Chest. 2016;149:27.
- Olson EJ (expert opinion). Mayo Clinic, Rochester, Minn. March 14, 2016.
- Irwin RS, et al. Diagnosis and management of cough executive summary: ACCP evidence-based clinical practice guidelines. Chest. 2006;129:1S.
- Schmitt BD. Pediatric Telephone Protocols. 15th ed. Elk Grove Village, Ill.: American Academy of Pediatrics; 2016:106.
- What is COPD? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/copd/. Accessed April 4, 2016.