What Is Bronchorrhea?

The excess discharge of watery mucus from the lungs

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Bronchorrhea is an excessive discharge of watery mucus from the lungs, more than normal phlegm, that results in a productive cough. A diagnosis is made when a person coughs up at least 100 cubic centimeters (cc) of fluid from their lungs daily, or about 20 teaspoons.

Bronchorrhea causes include lung cancer as among the most common. The excess mucus may be a symptom of bronchitis, bronchiectasis, and other conditions that affect the bronchi, the airway tubes that connect to your lungs.

This article discusses symptoms and causes of this condition. It explains bronchorrhea treatment that's focused on the underlying cause of the mucus as well as the reduction of the secretions.

An older man with bad cough at the doctor's office
Science Photo Library / Getty Images

Bronchorrhea Symptoms 

Bronchorrhea is a symptom in which large amounts of thin mucus are coughed up from a person's lungs on a daily basis. This is not just a little drainage and can be a cause for concern. Bronchorrhea tends to be at its worst in the morning and often improves throughout the day.

This symptom can result in a persistent cough to clear the fluid, and shortness of breath due to obstruction of the airways by mucus. Many health conditions also result in a cough and shortness of breath, and bronchorrhea can aggravate those symptoms.


Bronchorrhea and the excess mucus it causes are primarily a nuisance, though often a dramatic one. Still, it may result in dehydration and electrolyte imbalances in the body. When severe, it may also result in airway obstruction and respiratory distress.

How Is Bronchorrhea Diagnosed?

Evaluation for bronchorrhea is usually performed by taking a careful medical history and physical exam. Imaging studies and blood work are usually done as part of the work-up to determine a diagnosis. Tests and procedures may include:

  • Imaging, such as computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET)
  • Tuberculosis testing
  • Pulmonary function tests

Bronchorrhea Causes 

There are several causes of bronchorrhea, though thankfully it is a fairly uncommon condition. Possible causes include chronic respiratory and lung diseases.

Lung Diseases

Chronic lung diseases can lead to symptoms of bronchorrhea. These conditions include:

  • Chronic bronchitis, a form of chronic obstructive pulmonary disease (COPD) characterized by inflammation of the bronchi.
  • Bronchiectasis, an obstructive lung disease often caused by childhood respiratory infections. It results in mucus collection in the airways due to widening and dilation of the airways.
  • 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.

What Is Bronchospastic Cough?

With some conditions, the bronchi can tighten into a spasm. These bronchospasms are common with asthma and COPD, and cause wheezes, shortness of breath, and cough. It is common for excess mucus from bronchorrhea to arise with a bronchospastic cough, often in people who smoke.

Lung Cancer

There is a form of lung cancer which in the past was called mucinous bronchioloalveolar carcinoma (BAC). It is the most common cause of bronchorrhea.

BAC has now been reclassified as a form of lung adenocarcinoma but the symptom of excess phlegm is still the same for people living with the disease. With BAC, the incidence of bronchorrhea is estimated to be around 6%.

It is not uncommon for BAC, often with the excess mucus of bronchorrhea, to be mistaken for pneumonia or other lung diseases before it is diagnosed, sometimes for an extended period of time.


Tuberculosis has been associated with bronchorrhea, though this is less common in the United States.

Poisonings and Stings

Poisoning with chemicals known as organophosphates (anticholinesterase pesticides) is a serious cause of bronchorrhea. Scorpion stings may also be responsible.

Bronchorrhea Treatment

The best treatment for bronchorrhea is to find and treat the underlying cause, especially with lung cancer, and to understand the mechanism by which it occurs.


To understand the best treatment options, it's important to note that bronchorrhea is different than coughing up phlegm. It's believed that, for some reason, the airways become hyper-responsive to a particular stressor.

Bronchorrhea symptoms differ from mucus production associated with lung conditions caused by inflammation. Because of this, many traditional treatments for excess phlegm are ineffective.


Several different treatment options may reduce the symptoms of bronchorrhea, though they appear to give only moderate relief. These treatment options include:

  • Steroid medications and nonsteroidal anti-inflammatory inhalers (inhaled indomethacin). Indomethacin can take quite a while to work but has the potential to help over the long term.
  • Antibiotics known as macrolide antibiotics, such as Biaxin (clarithromycin) and Zithromax (azithromycin)
  • Sandostatin (octreotide), a man-made hormone that may be helpful for some people
  • Tryosine kinase inhibitors, such as Iressa (gefitinib) used for EGFR positive lung cancer. It has been very effective in treating bronchorrhea in some cases, quite apart from its independent role in shrinking tumors.

A Word From Verywell

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.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Shankar PS, Korukonda K, Bendre S, Behera D, Mirchandani L, Awad NT, et al. Diagnoses and management of adult cough: An Indian Environmental Medical Association (EMA) position paper. Respir Med. 2020 Jul;168:105949. doi:10.1016/j.rmed.2020.105949

  2. Remi C, Remi J, Bausewein C. Pharmacological Management of Bronchorrhea in Malignant Disease: A Systematic Literature Review. Journal of Pain and Symptom Management. 2016. 51(5):916-25. doi:10.1016/j.jpainsymman.2015.12.335

Additional Reading

By Lynne Eldridge, MD
 Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time."