Health Topics

Lungs and breathing

Respiratory Failure
National Library of Medicine
ARDS
Acute Respiratory Distress Syndrome
What is respiratory failure?

Respiratory failure is a condition in which your blood doesn't have enough oxygen or has too much carbon dioxide. Sometimes you can have both problems.

When you breathe, your lungs take in oxygen. The oxygen passes into your blood, which carries it to your organs. Your organs, such as your heart and brain, need this oxygen-rich blood to work well.

Another part of breathing is removing the carbon dioxide from the blood and breathing it out. Having too much carbon dioxide in your blood can harm your organs.

What causes respiratory failure?

Conditions that affect your breathing can cause respiratory failure. These conditions may affect the muscles, nerves, bones, or tissues that support breathing. Or they may affect the lungs directly. These conditions include

  • Diseases that affect the lungs, such as COPD (chronic obstructive pulmonary disease), cystic fibrosis, pneumonia, pulmonary embolism, and COVID-19
  • Conditions that affect the nerves and muscles that control breathing, such as amyotrophic lateral sclerosis (ALS), muscular dystrophy, spinal cord injuries, and stroke
  • Problems with the spine, such as scoliosis (a curve in the spine). They can affect the bones and muscles used for breathing.
  • Damage to the tissues and ribs around the lungs. An injury to the chest can cause this damage.
  • Drug or alcohol overdose
  • Inhalation injuries, such as from inhaling smoke (from fires) or harmful fumes
What are the symptoms of respiratory failure?

The symptoms of respiratory failure depend on the cause and the levels of oxygen and carbon dioxide in your blood.

A low oxygen level in the blood can cause shortness of breath and air hunger (the feeling that you can't breathe in enough air). Your skin, lips, and fingernails may also have a bluish color. A high carbon dioxide level can cause rapid breathing and confusion.

Some people who have respiratory failure may become very sleepy or lose consciousness. They also may have arrhythmia (irregular heartbeat). You may have these symptoms if your brain and heart are not getting enough oxygen.

How is respiratory failure diagnosed?

Your health care provider will diagnose respiratory failure based on

  • Your medical history
  • A physical exam, which often includes
    • Listening to your lungs to check for abnormal sounds
    • Listening to your heart to check for arrhythmia
    • Looking for a bluish color on your skin, lips, and fingernails
  • Diagnostic tests, such as
    • Pulse oximetry, a small sensor that uses a light to measure how much oxygen is in your blood. The sensor goes on the end of your finger or on your ear.
    • Arterial blood gas test, a test that measures the oxygen and carbon dioxide levels in your blood. The blood sample is taken from an artery, usually in your wrist.

Once you are diagnosed with respiratory failure, your provider will look for what is causing it. Tests for this often include a chest x-ray. If your provider thinks you may have arrhythmia because of the respiratory failure, you may have an EKG (electrocardiogram). This is simple, painless test that detects and records your heart's electrical activity.

What are the treatments for respiratory failure?

Treatment for respiratory failure depends on

  • Whether it is acute (short-term) or chronic (ongoing)
  • How severe it is
  • What is causing it

Acute respiratory failure can be a medical emergency. You may need treatment in intensive care unit at a hospital. Chronic respiratory failure can often be treated at home. But if your chronic respiratory failure is severe, you might need treatment in a long-term care center.

One of the main goals of treatment is to get oxygen to your lungs and other organs and remove carbon dioxide from your body. Another goal is to treat the cause of the condition. Treatments may include

  • Oxygen therapy, through a nasal cannula (two small plastic tubes that go in your nostrils) or through a mask that fits over your nose and mouth
  • Tracheostomy, a surgically-made hole that goes through the front of your neck and into your windpipe. A breathing tube, also called a tracheostomy, or trach tube, is placed in the hole to help you breathe.
  • Ventilator, a breathing machine that blows air into your lungs. It also carries carbon dioxide out of your lungs.
  • Other breathing treatments, such as noninvasive positive pressure ventilation (NPPV), which uses mild air pressure to keep your airways open while you sleep. Another treatment is a special bed that rocks back and forth, to help you breathe in and out.
  • Fluids, often through an intravenous (IV), to improve blood flow throughout your body. They also provide nutrition.
  • Medicines for discomfort
  • Treatments for the cause of the respiratory failure. These treatments may include medicines and procedures.

If you have respiratory failure, see your health care provider for ongoing medical care. Your provider may suggest pulmonary rehabilitation.

If your respiratory failure is chronic, make sure that you know when and where to get help for your symptoms. You need emergency care if you have severe symptoms, such as trouble catching your breath or talking. You should call your provider if you notice that your symptoms are worsening or if you have new signs and symptoms.

Living with respiratory failure may cause fear, anxiety, depression, and stress. Talk therapy, medicines, and support groups can help you feel better.

NIH: National Heart, Lung, and Blood Institute


Respiratory Insufficiency
Lungs and Breathing
... can have both problems. When you breathe, your lungs take in oxygen. The oxygen passes into your blood, which carries it to your organs. Your organs, such as your heart and brain, need this oxygen-rich blood to work well. Another part of breathing is removing the carbon dioxide from the blood ...
Cystic Fibrosis
National Library of Medicine
CF

Cystic fibrosis (CF) is an inherited disease of the mucus and sweat glands. It affects mostly your lungs, pancreas, liver, intestines, sinuses, and sex organs. CF causes your mucus to be thick and sticky. The mucus clogs the lungs, causing breathing problems and making it easy for bacteria to grow. This can lead to repeated lung infections and lung damage.

The symptoms and severity of CF can vary. Some people have serious problems from birth. Others have a milder version of the disease that doesn't show up until they are teens or young adults. Sometimes you will have few symptoms, but later you may have more symptoms.

CF is diagnosed through various tests, such as gene, blood, and sweat tests. There is no cure for CF, but treatments have improved greatly in recent years. In the past, most deaths from CF were in children and teenagers. Today, with improved treatments, some people who have CF are living into their forties, fifties, or older. Treatments may include chest physical therapy, nutritional and respiratory therapies, medicines, and exercise.

NIH: National Heart, Lung, and Blood Institute


Cystic Fibrosis
Lungs and Breathing
Genetics/Birth Defects
... be thick and sticky. The mucus clogs the lungs, causing breathing problems and making it easy for bacteria to grow. This can lead to repeated lung infections and lung damage. The symptoms and severity ...
Lung Diseases
National Library of Medicine
Respiratory Diseases

When you breathe, your lungs take in oxygen from the air and deliver it to the bloodstream. The cells in your body need oxygen to work and grow. During a normal day, you breathe nearly 25,000 times. People with lung disease have difficulty breathing. Millions of people in the U.S. have lung disease. If all types of lung disease are lumped together, it is the number three killer in the United States.

The term lung disease refers to many disorders affecting the lungs, such as asthma, COPD, infections like influenza, pneumonia and tuberculosis, lung cancer, and many other breathing problems. Some lung diseases can lead to respiratory failure.

Dept. of Health and Human Services Office on Women's Health


Lung Diseases
Lungs and Breathing
When you breathe, your lungs take in oxygen from the air and deliver it to the bloodstream. The cells in your body need oxygen to work and grow. During a ...
Inhalation Injuries
National Library of Medicine
Smoke Inhalation

Inhalation injuries are acute injuries to your respiratory system and lungs. They can happen if you breathe in toxic substances, such as smoke (from fires), chemicals, particle pollution, and gases. Inhalation injuries can also be caused by extreme heat; these are a type of thermal injuries. Over half of deaths from fires are due to inhalation injuries.

Symptoms of inhalation injuries can depend on what you breathed in. But they often include

  • Coughing and phlegm
  • A scratchy throat
  • Irritated sinuses
  • Shortness of breath
  • Chest pain or tightness
  • Headaches
  • Stinging eyes
  • A runny nose

If you have a chronic heart or lung problem, an inhalation injury can make it worse.

To make a diagnosis, your health care provider may use a scope to look at your airways and check for damage. Other possible tests include imaging tests of the lungs, blood tests, and lung function tests.

If you have an inhalation injury, your health care provider will make sure that your airway is not blocked. Treatment is with oxygen therapy, and in some cases, medicines. Some patients need to use a ventilator to breathe. Most people get better, but some people have permanent lung or breathing problems. Smokers and people who had a severe injury are at a greater risk of having permanent problems.

You can take steps to try to prevent inhalation injuries:

  • At home, practice fire safety, which includes preventing fires and having a plan in case there is a fire
  • If there is smoke from a wildfire nearby or lots of particulate pollution in the air, try to limit your time outdoors. Keep your indoor air as clean as possible, by keeping windows closed and using an air filter. If you have asthma, another lung disease, or heart disease, follow your health care provider's advice about your medicines and respiratory management plan.
  • If you are working with chemicals or gases, handle them safely and use protective equipment

Burns, Inhalation
Lungs and Breathing
Injuries and Wounds
... people get better, but some people have permanent lung or breathing problems. Smokers and people who had a severe ...
Collapsed Lung
National Library of Medicine
Atelectasis
Pneumothorax

A collapsed lung happens when air enters the pleural space, the area between the lung and the chest wall. If it is a total collapse, it is called pneumothorax. If only part of the lung is affected, it is called atelectasis.

Causes of a collapsed lung include

  • Lung diseases such as pneumonia or lung cancer
  • Being on a breathing machine
  • Surgery on the chest or abdomen
  • A blocked airway

If only a small area of the lung is affected, you may not have symptoms. If a large area is affected, you may feel short of breath and have a rapid heart rate.

A chest x-ray can tell if you have it. Treatment depends on the underlying cause.

NIH: National Heart, Lung, and Blood Institute


Pulmonary Atelectasis
Pneumothorax
Lungs and Breathing
... lung include Lung diseases such as pneumonia or lung cancer Being on a breathing machine Surgery on the chest or abdomen A blocked airway If only a small area of the lung is affected, you may not have symptoms. If ...
Pulmonary Rehabilitation
National Library of Medicine
Chest Physical Therapy
Lung Rehabilitation
What is pulmonary rehabilitation?

Pulmonary rehabilitation, also known as pulmonary rehab or PR, is a program for people who have chronic (ongoing) breathing problems. It can help improve your ability to function and quality of life. PR does not replace your medical treatment. Instead, you use them together.

PR is often an outpatient program that you do in a hospital or clinic. Some people have PR in their homes. You work with a team of health care providers to find ways to lessen your symptoms, increase your ability to exercise, and make it easier to do your daily activities.

Who needs pulmonary rehabilitation?

Your health care provider may recommend pulmonary rehabilitation (PR) if you have a chronic lung disease or another condition that makes it hard for you to breathe and limits your activities. For example, PR may help you if you

  • Have COPD (chronic obstructive pulmonary disease). The two main types are emphysema and chronic bronchitis. In COPD, your airways (tubes that carry air in and out of your lungs) are partially blocked. This makes it hard to get air in and out.
  • Have an interstitial lung disease such as sarcoidosis and pulmonary fibrosis. These diseases cause scarring of the lungs over time. This makes it hard to get enough oxygen.
  • Have cystic fibrosis (CF). CF is an inherited disease that causes thick, sticky mucus to collect in the lungs and block the airways.
  • Need lung surgery. You may have PR before and after lung surgery to help you prepare for and recover from the surgery.
  • Have a muscle-wasting disorder that affects the muscles used for breathing. An example is muscular dystrophy.

PR works best if you start it before your disease is severe. However, even people who have advanced lung disease can benefit from PR.

What does pulmonary rehabilitation include?

When you first start pulmonary rehabilitation (PR), your team of health care providers will want to learn more about your health. You will have lung function, exercise, and possibly blood tests. Your team will go over your medical history and current treatments. They may check on your mental health and ask about your diet. Then they will work together to create a plan that is right for you. It may include

  • Exercise training. Your team will come up with an exercise plan to improve your endurance and muscle strength. You will likely have exercises for both your arms and legs. You might use a treadmill, stationary bike, or weights. You may need to start slowly and increase your exercise as you get stronger.
  • Nutritional counseling. Being either overweight or underweight can affect your breathing. A nutritious eating plan can help you work towards a healthy weight.
  • Education about your disease and how to manage it. This includes learning how to avoid situations that make your symptoms worse, how to avoid infections, and how/when to take your medicines.
  • Techniques you can use to save your energy. Your team may teach you easier ways to do daily tasks. For example, you may learn ways to avoid reaching, lifting, or bending. Those movements make it harder to breathe, since they use up energy and make you tighten your abdominal muscles. You may also learn how to better deal with stress, since stress can also take up energy and affect your breathing.
  • Breathing strategies. You will learn techniques to improve your breathing. These techniques may increase your oxygen levels, decrease how often you take breaths, and keep your airways open longer.
  • Psychological counseling and/or group support. It can feel scary to have trouble breathing. If you have a chronic lung disease, you are more likely to have depression, anxiety, or other emotional problems. Many PR programs include counseling and/or support groups. If not, your PR team may be able to refer you to an organization that offers them.

NIH: National Heart, Lung, and Blood Institute


Lung Diseases
Lungs and Breathing
Surgery and Rehabilitation
... an organization that offers them. NIH: National Heart, Lung, and Blood Institute
Chronic Bronchitis
National Library of Medicine
Bronchitis
What is chronic bronchitis?

Chronic bronchitis is a type of COPD (chronic obstructive pulmonary disease). COPD is a group of lung diseases that make it hard to breathe and get worse over time. The other main type of COPD is emphysema. Most people with COPD have both emphysema and chronic bronchitis, but how severe each type is can be different from person to person.

Chronic bronchitis is inflammation (swelling) and irritation of the bronchial tubes. These tubes are the airways that carry air to and from the air sacs in your lungs. The irritation of the tubes causes mucus to build up. This mucus and the swelling of the tubes make it harder for your lungs to move oxygen in and carbon dioxide out of your body.

What causes chronic bronchitis?

The cause of chronic bronchitis is usually long-term exposure to irritants that damage your lungs and airways. In the United States, cigarette smoke is the main cause. Pipe, cigar, and other types of tobacco smoke can also cause chronic bronchitis, especially if you inhale them.

Exposure to other inhaled irritants can contribute to chronic bronchitis. These include secondhand smoke, air pollution, and chemical fumes or dusts from the environment or workplace.

Rarely, a genetic condition called alpha-1 antitrypsin deficiency can play a role in causing chronic bronchitis.

Who is at risk for chronic bronchitis?

The risk factors for chronic bronchitis include

  • Smoking. This the main risk factor. Up to 75% of people who have chronic bronchitis smoke or used to smoke.
  • Long-term exposure to other lung irritants, such as secondhand smoke, air pollution, and chemical fumes and dusts from the environment or workplace.
  • Age. Most people who have chronic bronchitis are at least 40 years old when their symptoms begin.
  • Genetics. This includes alpha-1 antitrypsin deficiency, which is a genetic condition. Also, smokers who get chronic bronchitis are more likely to get it if they have a family history of COPD.
What are the symptoms of chronic bronchitis?

At first, you may have no symptoms or only mild symptoms. As the disease gets worse, your symptoms usually become more severe. They can include

  • Frequent coughing or a cough that produces a lot mucus
  • Wheezing
  • A whistling or squeaky sound when you breathe
  • Shortness of breath, especially with physical activity
  • Tightness in your chest

Some people with chronic bronchitis get frequent respiratory infections such as colds and the flu. In severe cases, chronic bronchitis can cause weight loss, weakness in your lower muscles, and swelling in your ankles, feet, or legs.

How is chronic bronchitis diagnosed?

Your health care provider may use many tools to make a diagnosis:

  • A medical history, which includes asking about your symptoms
  • A family history
  • Various tests, such as lung function tests, a chest x-ray or CT scan, and blood tests
What are the treatments for chronic bronchitis?

There is no cure for chronic bronchitis. However, treatments can help with symptoms, slow the progress of the disease, and improve your ability to stay active. There are also treatments to prevent or treat complications of the disease. Treatments include

  • Lifestyle changes, such as
    • Quitting smoking if you are a smoker. This is the most important step you can take to treat chronic bronchitis.
    • Avoiding secondhand smoke and places where you might breathe in other lung irritants
    • Ask your health care provider for an eating plan that will meet your nutritional needs. Also ask about how much physical activity you can do. Physical activity can strengthen the muscles that help you breathe and improve your overall wellness.
  • Medicines, such as
    • Bronchodilators, which relax the muscles around your airways. This helps open your airways and makes breathing easier. Most bronchodilators are taken through an inhaler. In more severe cases, the inhaler may also contain steroids to reduce inflammation.
    • Vaccines for the flu and pneumococcal pneumonia, since people with chronic bronchitis are at higher risk for serious problems from these diseases.
    • Antibiotics if you get a bacterial or viral lung infection
  • Oxygen therapy, if you have severe chronic bronchitis and low levels of oxygen in your blood. Oxygen therapy can help you breathe better. You may need extra oxygen all the time or only at certain times.
  • Pulmonary rehabilitation, which is a program that helps improve the well-being of people who have chronic breathing problems. It may include
    • An exercise program
    • Disease management training
    • Nutritional counseling
    • Psychological counseling
  • A lung transplant, as a last resort for people who have severe symptoms that have not gotten better with medicines

If you have chronic bronchitis, it's important to know when and where to get help for your symptoms. You should get emergency care if you have severe symptoms, such as trouble catching your breath or talking. Call your health care provider if your symptoms are getting worse or if you have signs of an infection, such as a fever.

Can chronic bronchitis be prevented?

Since smoking causes most cases of chronic bronchitis, the best way to prevent it is to not smoke. It's also important to try to avoid lung irritants such as secondhand smoke, air pollution, chemical fumes, and dusts.

NIH: National Heart, Lung, and Blood Institute


Bronchitis, Chronic
Infections
Lungs and Breathing
... and places where you might breathe in other lung irritants Ask your health ... makes breathing easier. Most bronchodilators are taken through an inhaler. ...
Emphysema
National Library of Medicine
Pulmonary Emphysema
What is emphysema?

Emphysema is a type of COPD (chronic obstructive pulmonary disease). COPD is a group of lung diseases that make it hard to breathe and get worse over time. The other main type of COPD is chronic bronchitis. Most people with COPD have both emphysema and chronic bronchitis, but how severe each type is can be different from person to person.

Emphysema affects the air sacs in your lungs. Normally, these sacs are elastic or stretchy. When you breathe in, each air sac fills up with air, like a small balloon. When you breathe out, the air sacs deflate, and the air goes out.

In emphysema, the walls between many of the air sacs in the lungs are damaged. This causes the air sacs to lose their shape and become floppy. The damage also can destroy the walls of the air sacs, leading to fewer and larger air sacs instead of many tiny ones. This makes it harder for your lungs to move oxygen in and carbon dioxide out of your body.

What causes emphysema?

The cause of emphysema is usually long-term exposure to irritants that damage your lungs and the airways. In the United States, cigarette smoke is the main cause. Pipe, cigar, and other types of tobacco smoke can also cause emphysema, especially if you inhale them.

Exposure to other inhaled irritants can contribute to emphysema. These include secondhand smoke, air pollution, and chemical fumes or dusts from the environment or workplace.

Rarely, a genetic condition called alpha-1 antitrypsin deficiency can play a role in causing emphysema.

Who is at risk for emphysema?

The risk factors for emphysema include

  • Smoking. This the main risk factor. Up to 75% of people who have emphysema smoke or used to smoke.
  • Long-term exposure to other lung irritants, such as secondhand smoke, air pollution, and chemical fumes and dusts from the environment or workplace.
  • Age. Most people who have emphysema are at least 40 years old when their symptoms begin.
  • Genetics. This includes alpha-1 antitrypsin deficiency, which is a genetic condition. Also, smokers who get emphysema are more likely to get it if they have a family history of COPD.
What are the symptoms of emphysema?

At first, you may have no symptoms or only mild symptoms. As the disease gets worse, your symptoms usually become more severe. They can include

  • Frequent coughing or wheezing
  • A cough that produces a lot mucus
  • Shortness of breath, especially with physical activity
  • A whistling or squeaky sound when you breathe
  • Tightness in your chest

Some people with emphysema get frequent respiratory infections such as colds and the flu. In severe cases, emphysema can cause weight loss, weakness in your lower muscles, and swelling in your ankles, feet, or legs.

How is emphysema diagnosed?

Your health care provider may use many tools to make a diagnosis:

  • A medical history, which includes asking about your symptoms
  • A family history
  • Other tests tests, such as lung function tests, a chest x-ray or CT scan, and blood tests
What are the treatments for emphysema?

There is no cure for emphysema. However, treatments can help with symptoms, slow the progress of the disease, and improve your ability to stay active. There are also treatments to prevent or treat complications of the disease. Treatments include

  • Lifestyle changes, such as
    • Quitting smoking if you are a smoker. This is the most important step you can take to treat emphysema.
    • Avoiding secondhand smoke and places where you might breathe in other lung irritants
    • Ask your health care provider for an eating plan that will meet your nutritional needs. Also ask about how much physical activity you can do. Physical activity can strengthen the muscles that help you breathe and improve your overall wellness.
  • Medicines, such as
    • Bronchodilators, which relax the muscles around your airways. This helps open your airways and makes breathing easier. Most bronchodilators are taken through an inhaler. In more severe cases, the inhaler may also contain steroids to reduce inflammation.
    • Vaccines for the flu and pneumococcal pneumonia, since people with emphysema are at higher risk for serious problems from these diseases
    • Antibiotics if you get a bacterial or viral lung infection
  • Oxygen therapy, if you have severe emphysema and low levels of oxygen in your blood. Oxygen therapy can help you breathe better. You may need extra oxygen all the time or only at certain times.
  • Pulmonary rehabilitation, which is a program that helps improve the well-being of people who have chronic breathing problems. It may include
    • An exercise program
    • Disease management training
    • Nutritional counseling
    • Psychological counseling
  • Surgery, usually as a last resort for people who have severe symptoms that have not gotten better with medicines. There are surgeries to
    • Remove damaged lung tissue
    • Remove large air spaces (bullae) that can form when air sacs are destroyed. The bullae can interfere with breathing.
    • Do a lung transplant. This is might be an option if you have very severe emphysema.

If you have emphysema, it's important to know when and where to get help for your symptoms. You should get emergency care if you have severe symptoms, such as trouble catching your breath or talking. Call your health care provider if your symptoms are getting worse or if you have signs of an infection, such as a fever.

Can emphysema be prevented?

Since smoking causes most cases of emphysema, the best way to prevent it is to not smoke. It's also important to try to avoid lung irritants such as secondhand smoke, air pollution, chemical fumes, and dusts.

NIH: National Heart, Lung, and Blood Institute


Emphysema
Lungs and Breathing
What is emphysema? Emphysema is a type of COPD (chronic obstructive pulmonary disease). COPD is a group of lung diseases that make it hard to breathe and ...
Pleural Disorders
National Library of Medicine
Pleural Effusion
Pleurisy
Pneumothorax
Thoracentesis

Your pleura is a large, thin sheet of tissue that wraps around the outside of your lungs and lines the inside of your chest cavity. Between the layers of the pleura is a very thin space. Normally it's filled with a small amount of fluid. The fluid helps the two layers of the pleura glide smoothly past each other as your lungs breathe air in and out.

Disorders of the pleura include

  • Pleurisy - inflammation of the pleura that causes sharp pain with breathing
  • Pleural effusion - excess fluid in the pleural space
  • Pneumothorax - buildup of air or gas in the pleural space
  • Hemothorax - buildup of blood in the pleural space

Many different conditions can cause pleural problems. Viral infection is the most common cause of pleurisy. The most common cause of pleural effusion is congestive heart failure. Lung diseases, like COPD, tuberculosis, and acute lung injury, cause pneumothorax. Injury to the chest is the most common cause of hemothorax. Treatment focuses on removing fluid, air, or blood from the pleural space, relieving symptoms, and treating the underlying condition.

NIH: National Heart, Lung, and Blood Institute


Pleural Diseases
Lungs and Breathing
... pleura glide smoothly past each other as your lungs breathe air in and out. Disorders of the pleura include Pleurisy - inflammation of the pleura that causes sharp pain with breathing Pleural effusion - excess fluid in the pleural space ...
Bronchial Disorders
National Library of Medicine
Bronchiectasis
Bronchiolitis

When you breathe in, the air travels down through your trachea (windpipe). It then goes through two tubes to your lungs. These tubes are your bronchi. Bronchial disorders can make it hard for you to breathe.

The most common problem with the bronchi is bronchitis, an inflammation of the tubes. It can be acute or chronic. Other problems include

  • Bronchiectasis - a condition in which damage to the airways causes them to widen and become flabby and scarred
  • Exercise-induced bronchospasm - a breathing problem that happens when your airways shrink while you are exercising
  • Bronchiolitis - an inflammation of the small airways that branch off from the bronchi
  • Bronchopulmonary dysplasia - a chronic lung condition in infants, most often premature infants

Bronchial Diseases
Lungs and Breathing
... It then goes through two tubes to your lungs. These tubes are your bronchi. ... - a breathing problem that happens when your airways shrink while ...