Bronchorrhea Symptoms, Causes, and Treatments

man spitting phlegm into a tissue PhotoDean Drobot

What is the definition bronchorrhea and what are some possible causes? When bronchorrhea occurs with lung cancer or other lung conditions, what are the best treatments and how can the symptoms be managed?

Bronchorrhea is defined as an excessive discharge of watery mucus from the lungs, which results in a productive cough. This discharge is much copious than normal phlegm, and by definition occurs only when a person coughs up at least the equivalent of 20 teaspoons of mucus daily from their lungs.


Bronchorrhea is a symptom in which large amounts of thin mucus is coughed up from a person's lungs daily. This is not just a little drainage and can be an incredibly annoying symptom. This symptom tends to be at its worst in the morning and often improves through the day.

This symptom can result in a cough (to clear the fluid) and shortness of breath. Since many of the conditions which cause bronchorrhea can also result in a cough and shortness of breath, bronchorrhea can aggravate those symptoms tremendously.

Bronchorrhea is different than coughing up phlegm or sputum. It's thought to be due to the airways being "hyperresponsive" to a stressor. Unlike the airway hypersensitivity that occurs with airway constriction such as asthma, this condition causes "secretory hyperresponsiveness."


The diagnosis of bronchorrhea is a clinical diagnosis (it is made by history and physical alone) and is defined as the production of more than 100 cc's (more than 20 teaspoons) of mucus daily.


There are several causes of bronchorrhea, though thankfully it is a fairly uncommon condition. Possible causes include:

  • Lung cancer: A form of lung cancer which in the past was called mucinous bronchioloalveolar carcinoma (BAC), is the most common cause of bronchorrhea. BAC has now been reclassified as a form of lung adenocarcinoma, but still causes this bothersome drainage for people living with the new diagnosis.
  • Chronic bronchitis: Chronic bronchitis is a form of chronic obstructive pulmonary disease (COPD) characterized by inflammation of the bronchi.
  • Asthma, especially cough-variant asthma: Cough-variant asthma is an atypical form of asthma in which the only symptom at the time of diagnosis is a cough.
  • Some poisonings: Poisoning with chemicals known organophosphates (anticholinesterase pesticides) is a serious cause of bronchorrhea.
  • Tuberculosis
  • Bronchiectasis: Bronchiectasis is a form of COPD often caused by childhood respiratory infections, which results in mucus collection in the airways due to widening and dilation of the airways.


While bronchorrhea is mostly a nuisance (though often very dramatic), it may result in abnormalities in the body's electrolytes. When severe, it may also result in obstruction of the airways and respiratory distress.

Treatments Associated With Lung Cancer

The best treatment for bronchorrhea is to find and treat the underlying cause, especially with lung cancer.

For those with lung adenocarcinoma with bronchorrhea, sometimes significant and very dramatic improvement has been noted with using the medications Tarceva (erlotinib) and Iressa (gefitinib). These medications target an EGFR mutation present in some lung cancers, especially lung adenocarcinomas, a type of non-small cell lung cancer. It's now felt that everyone diagnosed with lung adenocarcinoma (and non-small cell lung cancer in general) should undergo genetic testing (molecular profiling) to check for the presence of treatable (targetable) mutations such as EGFR mutationsALK rearrangementsROS1 rearrangements, and others.

When bronchorrhea occurs in association with poisoning (usually pesticide exposure) treatment of the poisoning is of most importance.

Several different treatment options have been tried in an effort to reduce the symptoms of bronchorrhea. While these appear to give only moderate relief, steroids and non-steroidal anti-inflammatory inhalers or a class of antibiotics known as macrolide antibiotics may be of some benefit. The man-made hormone octreotide may also be helpful for some people.

Bottom Line

Bronchorrhea is a relatively uncommon symptom in which large amounts of a watery discharge are coughed up from the lungs. It may occur with lung cancer, particularly some types, as well as other lung conditions. Since lung adenocarcinoma appears to be increasing, especially in young adults with lung cancer and people who have never smoked, it's likely that this symptom will be on the rise.

The symptom may be treated symptomatically with steroid or NSAID inhalers, but the greatest benefit lies in treating underlying cancer.

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