Causes and Risk Factors for Bronchiectasis

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Bronchiectasis can happen to anyone of any age, but the condition seems to be more common in women and people over age 65. Bronchiectasis is often caused by cystic fibrous (CF), a genetic condition that causes long-lasting infections of the lungs and breathing problems. CF is a progressive condition, which means it gets worse over time.

In at least half of the cases of bronchiectasis, no specific cause can be determined.  Non-CF cases of bronchiectasis—called idiopathic bronchiectasis—often result from recurrent infections, aspiration, and airway obstructions. Lifestyle and environmental factors can also contribute to the development of the conditions. 

common causes of bronchiectasis

Verywell / Jiaqi Zhou

Common Causes

Infections, aspiration, and airway obstruction are common acquired conditions that may, over time, result in the development of bronchiectasis.


Damage to the walls of the airways is the most common cause of bronchiectasis. Lung infections are notorious for causing this type of damage. Examples of infections that contribute to bronchiectasis include:

  • Severe pneumonia: Pneumonia is a lung infection that is caused by bacteria, viruses, or fungi. It causes the air sacs of the lungs to become inflamed and fill up with fluid. Pneumonia can make it harder for oxygen you breathe in to get into the bloodstream. Symptoms can be mild to severe, and include cough, fever, chills, and breathing troubles.
  •  Whooping cough: While rare in the United States due to vaccines, whooping cough is a highly contagious respiratory tract infection. It is marked by a severe hacking cough and a high-pitched breath that makes a “whoop” sound.
  •  Tuberculosis (TB): TB is a potentially serious bacterial infection that mainly affects the lungs. Symptoms of TB include a bad cough lasting three or more weeks, chest pain, and coughing up blood or mucus from deep inside the lungs.
  • Fungal infections: Any infection that is caused by a fungus. Fungal infections in the lungs can be very serious and cause symptoms similar to other illness, including tuberculous. 

All of these infections are known for damaging the airways, potentially resulting in bronchiectasis.


Chronic pulmonary aspiration is the result of inhaling oral or stomach materials into the lungs. When aspiration is severe or recurrent, it can lead to inflammation of airways and cause bronchiectasis. This can happen from: 

  • Oropharyngeal dysphagia: This condition affects a person’s ability to shallow, potentially causing saliva or food to enter the lungs.
  • Gastroesophageal reflux disease (GERD): GERD occurs when the valve of the smooth muscle between the esophagus and the stomach isn’t functioning correctly, allowing stomach contents to flow back up to the esophagus. Stomach contents may enter the lungs and irritate the airways. Symptoms of GERD include heartburn, chest pain, problems with swallowing, regurgitation of food or sour liquid, and feeling of a lump in the throat.

Airway Obstruction

An obstructed airway can trap mucus and cause infection behind the obstruction that eventually leads to airway damage,

A tumor can also cause obstruction of an airway. An inhaled object—for example, a peanut or a piece of toy—can eventually result in bronchiectasis.

Risk Factors

Some people have specific risk factors for the development of bronchiectasis. These are generally ones they don’t have a lot of control over. These include gender, age, congenital conditions (conditions a person has since birth), allergies, and some diseases.


While bronchiectasis can develop at age, most of the people who have this condition are women. In children, however, the condition affects more boys than girls.

Bronchiectasis seems to affect women more harshly and more often than men. Researchers believe this has to do with increased inflammatory responses and exposures.


According to the Cleveland Clinic, there are up to 500,000 people in the United States with bronchiectasis and of that number, one of 150 people are age 75 or older. The risk of bronchiectasis increases with age.

Research reported in the journal, Clinical Interventions in Aging, finds that more than half of the people with bronchiectasis are over age 65 and the condition tends to be much worse in the elderly. Most of these bronchiectasis cases are related to severe lung infections and respiratory problems. 

Cystic Fibrosis

Cystic fibrosis affects up to 30,000 people in the United States. It is the result of a defective gene protein that causes the body to produce thick sticky mucus that clogs the lungs and leads to life-threatening lung infections and airway destruction. Bronchiectasis is connected to CF, resulting from permanent enlargement and obstruction of the airway.

Allergic Bronchopulmonary Aspergillosis

This condition is the result of an allergic reaction to a fungus called aspergillosis. The reaction causes the airways to swell, eventually causing damage.

Cilia Function Disorders

Any disorder affecting cilia function can cause damage to the airways. The cilia are small hair-like structures lining the airways. Their job is to keep the airways clear of mucus and dirt.

Primary ciliary dyskinesia is an inherited cilia disorder where the cilia don’t work properly and cannot clean secretions effectively. Having this condition can put a person at risk for recurrent infections and long-term airway damage.

Immune Deficiencies

People who have immune deficiencies, including antibody deficiencies, are more likely to have repeated infections. Immune deficiency disorders are ones where the immune system goes off track and has a weaker response to threats. The low activity is called immune deficiency and it makes it harder to fight off infections.

These deficiencies can be the result of illness or medication, or are present at birth, as with a genetic disorder known as a primary immune deficiency. Because of increased susceptibility and weakened immune status, infections can be serious enough to damage airways.

Autoimmune Disease

Much like immune deficiency disorders, autoimmune diseases, such as rheumatoid arthritis (RA), lupus, and Sjogren’s syndrome, can increase your risk for infections. Autoimmune diseases are disorders where the body’s immune system malfunctions and attacks healthy cells.

Many of the causes and risk factors for bronchiectasis are ones you may not be able to control. It is therefore important to be aware of the symptoms associated with this condition if you have any of the risk factors for developing it.

Lifestyle and Environmental Causes

Additional causes are related to bronchiectasis are environmental and chemical exposure and alcohol and drug abuse.


Some environmental factors may contribute to the exacerbation of bronchiectasis. For example, inhaled toxins, such as ammonia or other toxic gases and liquids can damage the lungs and lead to bronchiectasis. 

One 2018 study, from researchers out of Barcelona, Spain, looked for connections between environmental factors and hospitalizations for bronchiectasis. The observational study—conducted at two hospitals in Barcelona—looked at the number of hospitalizations related to bronchiectasis between 2007 to 2015. What they found was that temperature, pollution, and a variety of atmospheric conditions were associated with exacerbation of the condition.

They speculate that geographical location, along with environmental factors, also play a part in the development of bronchiectasis, but further study was needed to confirm their theories and findings.

Alcohol Abuse 

Heavy alcohol and drug use can cause damage to the lungs and increase the risk for bronchiectasis. 

Drug Abuse

Drug abuse leads to a variety of respiratory problems and lung and airway damage. Some drugs can slow breathing, block air from entering the lungs, or make symptoms of asthma and COPD worse, further increasing a person’s risk for bronchiectasis.

Frequently Asked Questions

  • Is bronchiectasis serious?

    It can be, in that it's a chronic condition with no cure. About half of cases of bronchiectasis are caused by cystic fibrosis, which is a severe and progressive respiratory disease. That said, bronchiectasis can almost always be managed, and people who develop it tend to live healthy lives and have a relatively normal lifespan.

  • What bacteria can cause bronchiectasis?

    The bacteria most often associated with infections that lead to bronchiectasis are Streptococcus pneumoniae and Pseudomonas aeruginosa. Among others that have been implicated are Klebsiella pneumonia, Mycobacterium tuberculosis, Moraxella catarrhalis, Haemophilus influenzae, Escherichia coli, and Staphylococcus aureus.

  • Why does bronchiectasis cause you to cough up blood?

    Hemoptysis, the clinical term for coughing up blood, occurs as a symptom of bronchiectasis when capillaries lining the mucus membranes of the trachea and bronchi become engorged with blood and then are damaged as a result of forceful coughing. The blood typically is mixed with mucus, or sputum, and appears as red or rust-colored streaks.

  • What is a bronchiectasis exacerbation?

    An exacerbation, or flare, of bronchiectasis occurs when three or more of the following symptoms develop and persist for at least 48 hours:

    • Severe cough
    • An increase in the amount and/or thickness of mucus that comes up with coughing
    • Pus that comes up with the cough
    • Trouble breathing that may or may not occur with exercise
    • Fatigue
    • Hemoptysis (coughing up blood)

    Bronchiectasis flares often are triggered when a new upper respiratory infection takes hold or an existing one gets worse.

10 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. Cleveland Clinic. Bronchiectasis

  2. Quinn TM and Hill AT. Non-cystic fibrosis bronchiectasis in the elderly: current perspectives. Clin Interv Aging. 2018; 13: 1649–1656. doi:10.2147/CIA.S143139

  3. Agrawal A, Agarwal A, Mehta D, et al. Nationwide trends of hospitalizations for cystic fibrosis in the United States from 2003 to 2013. Intractable Rare Dis Res. 2017 Aug; 6(3): 191–198. doi:10.5582/irdr.2017.01043

  4. Garcia-Olivé I, Radua J, Sánchez-Berenguer D, et al. Association between environmental factors and hospitalisations for bronchiectasis in Badalona, Barcelona, Spain (2007-2015). Med Clin (Barc). 2018 Apr 13;150(7):257-261. doi: 10.1016/j.medcli.2017.06.022

  5. National Institute on Drug Abuse.  Health Consequences of Drug Misuse.

  6. Cleveland Clinic. Bronchiectasis.

  7. Bopaka RG, El Khattabi W, Janah H, et al. Bronchiectasis: a bacteriological profilePan Afr Med J. 2015;22:378. doi:10.11604/pamj.2015.22.378.7775

  8. Ittrich H, Bockhorn M, Klose H, et al. The diagnosis and treatment of hemoptysisDtsch Arztebl Int. 2017;114(21):371-381. doi:10.3238/arztebl.2017.0371

  9. Merck Manual Professional Version. Bronchiectasis.

  10. Merck Manual Consumer Version. Bronchiectasis.

Additional Reading

By Lana Barhum
Lana Barhum has been a freelance medical writer since 2009. She shares advice on living well with chronic disease.