Bronchi

What are bronchi?

Your bronchi (BRON-kai) are large tubes that air travels down to get to your lungs. You have two main bronchi (left and right) that connect to the bottom of your trachea (windpipe) in your chest. Your left bronchus and right bronchus divide into smaller bronchi further into your lungs. (Bronchus is the singular of bronchi.)

Your bronchi are an essential part of your respiratory system. They’re part of a network of tubes (airways) that bring air in through your nose or mouth and direct it to the air sacs in your lungs (alveoli).

What do your bronchi do?

Your bronchi work as passageways that carry air to and from your lungs. As you breathe and your lungs expand, your bronchi distribute the air within your lungs.

Your bronchi are lined with mucus, which moisturizes the air along the way and traps foreign particles, like viruses, bacteria and dust. Cilia (hairlike structures) in your bronchi push trapped germs and other particles out of your body when you cough or sneeze.

Your bronchi are a part of your respiratory system. When you inhale:

1. Air passes from your mouth to your trachea, which divides into your left and right bronchi.
2. The air moves into your bronchi.
3. At the end of your bronchi, your bronchioles carry air to your alveoli. There, oxygen transfers from your lungs to your blood.

Carbon dioxide enters your lungs from your blood as it picks up oxygen. When you exhale, your bronchioles, bronchi and the rest of your airways push carbon dioxide out of your lungs with the air you breathe out.

Where are your bronchi located?

Your bronchi are located in your lungs, which are inside your rib cage in your chest. They connect to the bottom of your trachea. They start with large tubes and branch off into smaller tubes, eventually leading to your smallest airways (bronchioles).

What are the parts of the bronchi?

Your bronchi start off as two large tubes and branch off into segments. The different parts of your bronchi include:

• Primary (main) bronchi. These are the first parts of your bronchi — the left and right bronchi in the center part of your lungs. They’re the widest part of your bronchi and attach to your trachea.
• Secondary (lobular) bronchi. These are the second parts of your bronchi, near the middle of your lungs. They’re the parts of your bronchi that cross into the lobes of your lungs.
• Tertiary (segmental) bronchi. These are the third parts of your bronchi. They pass through a segment of each lobe, just before branching into bronchioles.

What’s the structure of the bronchi?

Your bronchi are made up of smooth muscle surrounded by cartilage. This provides support and controls air flow. Your primary bronchi are supported by cartilage rings. Your secondary and tertiary bronchi are smaller and have patches of cartilage instead. Mucus membranes and cilia line your bronchi.

Your bronchi are part of the tracheobronchial tree, which includes your trachea, bronchi and bronchioles. Your tracheobronchial tree looks like an upside-down tree with the trachea as the trunk and the bronchi representing the branches.

What conditions and disorders affect your bronchi?

Conditions that can affect your bronchi include:

• Asthma: Chronic inflammation in your airways that makes it difficult to breathe
• Bronchiectasis: Widening of and damage to your bronchi, causing mucus-filled pouches
• Bronchitis: Inflammation in your bronchi that may be short-term (acute) or long-lasting (chronic)
• Bronchopulmonary dysplasia: A breathing condition that can affect newborns whose lungs don’t develop properly
• Chronic obstructive pulmonary disease (COPD): A group of inflammatory lung diseases that can block your airways and affect your breathing
• Cystic fibrosis (CF): A genetic condition that causes thick, sticky mucus to build up in your airways

What are common symptoms of issues?

Symptoms of conditions that affect your bronchi include:

• Cough
• Shortness of breath
• Wheezing
• Coughing up blood
• Chest tightness
• Fatigue
• Frequent respiratory infections

What tests check bronchi health?

Depending on your symptoms, your healthcare provider may use pulmonary function tests to check the health of your bronchi and lungs. One of the most common pulmonary function tests is spirometry, which measures how much air you can hold and how forcefully you can exhale it.

Other common tests include:

• Bronchoscopy. Your provider uses a small, flexible tube with a camera to view inside your bronchi.
• CT scan. Your provider uses special computers and X-ray images to look at your lungs from different angles.
• Endobronchial ultrasound (EBUS). This is a type of bronchoscopy to diagnose inflammation or cancer.
• Exhaled nitric oxide test. This measures how much nitric oxide you exhale, which can tell providers if your bronchi are inflamed.

What are some common treatments for conditions that affect your bronchi?

Treatments depend on the condition affecting your bronchi. Some common treatments include:

• Inhaled medications. Bronchodilators and steroids can reduce inflammation and open your airways. These might come in an inhaler or as a liquid you put in a nebulizer.
• Oxygen therapy. You may need supplemental oxygen if you’re not getting enough.
• Pulmonary rehabilitation. This is an exercise and education program that can strengthen your lungs and help you manage lung conditions.
• Oral medications. You might take daily medication or take a course of medication (like steroids or antibiotics) when you have an infection or a flare-up.
• Positive airway pressure. Your provider might have you use a CPAP or BiPAP® machine to keep your airways open.

How can I keep my bronchi healthy?

Ways to keep your bronchi and the rest of your airways healthy include:

• Don’t smoke or vape
• Avoid secondhand smoke
• Clean your home and change air filters regularly
• Get regular physical activity to strengthen your heart and lungs
• Limit your exposure to air pollution
• Use protective gear like a face mask if you’re often around dust, allergens or chemical fumes
• Reduce your risk of respiratory infections by washing your hands, avoiding crowds during flu season and getting recommended vaccinations

When should I call my healthcare provider?

Contact a healthcare provider if you have a nagging cough or feel like you’re not breathing as well as you could be.

Call 911 or go to your nearest emergency room if you experience any signs of respiratory distress. These include:

• Bluish, gray or pale lips, skin or nails (cyanosis)
• Chest retractions, when your chest appears to sink in with each breath
• Faster breathing with no known cause
• Nose flaring
• Sweating with no increase in body temperature
• Wheezing