Bronchiectasis is a long-term lung condition where the airways become permanently damaged and widened, making it difficult for the body to clear mucus and leading to frequent infections that can worsen over time.
Understanding How Common Bronchiectasis Is
Bronchiectasis affects a significant number of people, though the exact figures may be higher than reported because some individuals have the condition without experiencing any symptoms. In the United States, approximately 350,000 to 500,000 people are living with bronchiectasis. The condition becomes more common as people age, affecting about one out of every 150 people who are 75 years old or older.[1]
Recent evidence suggests that the number of people diagnosed with bronchiectasis has been rising over the past few years. The condition disproportionately affects women and older individuals, and it may be contributing to an increasing healthcare burden. While bronchiectasis can occur at any age, it generally occurred more frequently in childhood during the period before antibiotics became widely available.[5]
The global statistics also indicate that the incidence of bronchiectasis is not entirely understood, and the condition can exist across all age groups. Many cases may go undiagnosed because people can have bronchiectasis without knowing it, especially if their symptoms are mild or absent.[1]
What Causes Bronchiectasis
The causes of bronchiectasis are varied and complex. In many cases, the exact cause remains unknown, which presents challenges for both diagnosis and treatment. Roughly 50 percent of cases of non-cystic fibrosis bronchiectasis have no identifiable cause.[8]
Historically, the most common cause was thought to be a previous respiratory infection, often during childhood. These infections can damage the walls of the airways, leading to the permanent widening that characterizes bronchiectasis. The condition usually results from an infection or other condition that injures the walls of the airways or prevents them from clearing the mucus they produce.[3]
Bacterial infections that can lead to bronchiectasis include Mycobacterium tuberculosis (which causes tuberculosis), Haemophilus influenzae, Pseudomonas aeruginosa, Staphylococcus aureus, and Mycoplasma. Viral infections such as respiratory syncytial virus and measles can also contribute to the development of this condition. Fungal infections represent another potential cause.[5]
Cystic fibrosis, a genetic disorder that affects the lungs and other organs, is the most common underlying condition associated with bronchiectasis. Nearly half of all bronchiectasis cases in the United States are related to cystic fibrosis. In children with cystic fibrosis, bronchiectasis commonly develops, affecting 50 to 75 percent of children by the age of 3 to 5 years.[3][7]
Other congenital or genetic conditions can also lead to bronchiectasis. These include primary ciliary dyskinesia, a condition that affects the tiny hair-like structures in the airways, and alpha-1 antitrypsin deficiency, which can also cause chronic obstructive pulmonary disease. Young syndrome and Mounier-Kuhn syndrome are additional rare genetic causes.[5]
Bronchial obstruction from various sources can result in bronchiectasis. Foreign bodies that have been inhaled, mucus plugs, tumors, or enlarged lymph nodes in the chest can all block the airways and lead to damage over time. Chronic aspiration, where food or stomach contents are repeatedly breathed into the lungs, and gastroesophageal reflux disorder can also contribute.[5]
Inflammatory and autoimmune diseases play a role in some cases. Conditions such as rheumatoid arthritis, Sjögren syndrome, ulcerative colitis, and inflammatory bowel disease have been associated with bronchiectasis. Allergic bronchopulmonary aspergillosis, a type of allergic lung inflammation caused by a reaction to Aspergillus fungus, can also damage the airways.[5][6]
Various lung conditions can occur alongside bronchiectasis or contribute to its development. These include severe asthma, chronic obstructive pulmonary disease (which is reported in up to 35 to 50 percent of patients with moderate-to-severe cases), diffuse panbronchiolitis, idiopathic pulmonary fibrosis (which can cause traction bronchiectasis), and bronchomalacia.[3][5]
Risk Factors for Developing Bronchiectasis
Certain groups of people face a higher risk of developing bronchiectasis. You are at increased risk if you are living with an underlying condition that affects your lungs or immune system. Without such a condition, your risk naturally increases as you get older.[1]
Inherited conditions significantly raise the risk. These include cystic fibrosis, alpha-1 antitrypsin deficiency, and primary ciliary dyskinesia. People born with these genetic conditions often develop bronchiectasis as a complication of their primary illness.[8]
Conditions that impair immune defenses make individuals more susceptible. Humoral immune deficiency, where the body cannot produce enough antibodies, affects 53 percent of adults with common variable immunodeficiency who also develop bronchiectasis. HIV infection and other immunodeficiency syndromes also increase vulnerability to the repeated infections that can lead to airway damage.[3][5]
Severe or chronic lung infections represent a major risk factor. Tuberculosis, pneumonia, whooping cough, and other serious respiratory infections that damage the airways during childhood or later in life can lead to bronchiectasis. Breathing in food particles or inhaling a foreign object during childhood can also initiate the process.[6]
Rheumatologic diseases create additional risk. Conditions such as rheumatoid arthritis and Sjögren disease are associated with the development of bronchiectasis. Leukemia and related cancers also increase the likelihood of developing this lung condition.[5][6]
Gender appears to play a role, with bronchiectasis being more common in women. Age is another significant factor, as the risk increases substantially in older adults. The condition can be present from birth, though this is rare, or it can develop later in life as a result of accumulated damage from infections and other factors.[5][6]
Recognizing the Symptoms of Bronchiectasis
The main symptom of bronchiectasis is a cough that does not go away and produces large amounts of mucus. This mucus, also called phlegm or sputum, may be clear, white, yellow, or green in color. In some cases, the mucus may smell bad or contain pus. People with bronchiectasis often cough up a lot of this thick substance as their body tries to remove it from the damaged airways.[1][4]
Getting frequent chest infections is another hallmark of the condition. During these episodes, symptoms worsen for a few days or weeks, and people may feel generally unwell. These repeated infections occur because bacteria grow in the pooled mucus, creating a cycle where infections cause more damage, which leads to more mucus buildup and more infections.[4]
Shortness of breath, known medically as dyspnea, commonly affects people with bronchiectasis. This breathlessness often gets worse during physical activity or exercise. The damaged airways cannot move air in and out of the lungs efficiently, making it harder to breathe, especially when the body needs more oxygen.[1][6]
Wheezing is another symptom that people may experience. This is a whistling or squeaky sound that occurs when breathing. Along with wheezing, some people notice other abnormal breathing sounds, such as crackling in the lungs, snoring sounds, or high-pitched squeaks.[1][4]
Coughing up blood, called hemoptysis, can occur in bronchiectasis, though it is less common in children. This may range from small spots or streaks of blood in the sputum to larger amounts. Any blood in the mucus should be reported to a healthcare provider promptly.[1]
General symptoms often include feeling very tired or run down. Many people experience chronic fatigue that affects their daily activities. Chest pain can also occur, particularly when breathing or coughing. Low-grade fever, chills, and night sweats may accompany infections.[4][6]
In some cases, people develop nail clubbing, which is characterized by swollen fingertips with curved nails. This sign, though rare, can indicate chronic lung disease. Some individuals may also notice that their breath has an unpleasant odor.[1][6]
Symptoms often come and go in severity. You might have stretches of time where your symptoms are not as bad, followed by periods when they worsen significantly. These flare-ups, called exacerbations, require prompt medical attention and often need treatment with antibiotics.[1]
Ways to Prevent Bronchiectasis
While not all cases of bronchiectasis can be prevented, especially those related to genetic conditions, there are important steps you can take to reduce your risk of developing this condition or to prevent it from worsening if you already have lung problems.
Getting vaccinated is one of the most effective preventive measures. Childhood vaccines help protect against serious respiratory infections that can damage the airways. The annual influenza vaccine is particularly important because flu can lead to severe lung infections. The pneumococcal vaccine, which protects against pneumonia, is also recommended. Vaccines for measles, rubeola (German measles), and pertussis (whooping cough) should be confirmed as up to date.[6][8]
Promptly treating lung infections is crucial. When you develop a respiratory infection, seeking medical care early and completing the full course of any prescribed antibiotics can prevent the kind of severe damage to the airways that leads to bronchiectasis. This is especially important for children, as many cases of bronchiectasis begin with a serious lung infection during childhood.[6]
Avoiding exposure to secondhand smoke and other toxic fumes, gases, and harmful substances protects your lungs from damage. If you smoke, quitting is one of the best things you can do for your respiratory health. Smokers with bronchiectasis have a higher risk of death from any cause compared to nonsmokers with the condition.[17][22]
Good hand hygiene helps prevent respiratory infections. Washing your hands frequently, especially before eating, reduces your risk of picking up viruses and bacterial infections that could lead to lung problems. As people with bronchiectasis are at higher risk of acquiring infections, this simple practice becomes even more important.[20]
If you have underlying conditions that can lead to bronchiectasis, managing them effectively is essential. This includes following treatment plans for conditions like cystic fibrosis, immune deficiency disorders, or rheumatologic diseases. Regular medical care and monitoring can help catch problems early before significant airway damage occurs.[8]
Being cautious about potential aspiration risks matters, particularly for people who have trouble swallowing or who have gastroesophageal reflux disease. Chronic aspiration of food or stomach contents into the lungs can lead to repeated infections and eventual bronchiectasis. Proper management of these conditions can reduce this risk.[5]
How Bronchiectasis Affects the Body
To understand how bronchiectasis affects the body, it helps to know how healthy airways normally work. The tubes going into your lungs, called airways or bronchi, have several built-in defenses to protect you from disease. When you breathe air in, any harmful particles get trapped in mucus that lines these airways. This mucus is not just there to cause problems; it is actually a protective mechanism.[1]
In healthy lungs, millions of tiny, hair-like structures called cilia line the airways. These cilia move in a coordinated, wave-like motion to push the mucus upward and out of your lungs, similar to how waves bring debris to the shore. This process is called mucociliary clearance. You then cough out the mucus or swallow it, and any trapped particles are destroyed by your stomach acid. This system normally works continuously to keep your lungs clean.[1]
In bronchiectasis, this protective system breaks down. The three most important mechanisms involved in the development of bronchiectasis are airway obstruction, infection, and peribronchial fibrosis, which is scarring around the airways. These factors work together in what is often described as a vicious cycle or vicious vortex.[5]
The damage to the airways causes them to widen permanently and become weak. Instead of being firm, smooth tubes, they develop pouches or become irregularly shaped. Healthcare providers categorize the types of damage as cylindrical (or tubular), varicose, or cystic, based on how the airways look. Cylindrical bronchiectasis is the most common and least serious form, while cystic bronchiectasis is the most severe.[1]
When the airways are damaged, they slowly lose their ability to clear out mucus. If the cilia are damaged or if the airways have pockets that trap mucus, the mucus builds up in the lungs. This creates an environment where harmful bacteria can grow much more easily. The mucus has bacteria trapped in it, which multiply and cause infections.[1][3]
These repeated infections cause inflammation, which is the body’s response to injury or infection. The inflammation damages the walls of the airways even further, making them wider and weaker. Each infection causes more damage, which leads to more mucus accumulation, which leads to more infections. This creates a self-perpetuating cycle where the condition progressively worsens.[1]
The damaged airways cannot perform the essential function of moving air in and out of your lungs efficiently. Over time, they lose their ability to clear mucus and their capacity to move adequate amounts of air. This reduced airflow makes it harder for your body to get enough oxygen and to remove carbon dioxide, especially during physical activity.[3]
The buildup of infected mucus and the ongoing inflammation can lead to permanent changes in lung structure. The walls of the airways become thickened from chronic inflammation and scarring. In some cases, scarring in the lungs can pull the airways out of shape, a specific type called traction bronchiectasis.[1]
Bronchiectasis can affect just one section of a lung, which is called focal bronchiectasis, or it can affect many sections throughout both lungs, known as diffuse bronchiectasis. The extent and severity of the damage determine how much the condition affects a person’s breathing and overall health.[1]
In severe cases that have progressed over many years, bronchiectasis can lead to serious complications. The constant struggle to breathe can strain the heart, potentially leading to a condition called cor pulmonale, where the right side of the heart becomes enlarged. Repeated bleeding in the lungs and low oxygen levels can occur in advanced disease.[6]
