Bronchitis

Your lungs are located inside the ribcage in your chest.  Your diaphragm is beneath your lungs.  The diaphragm is a dome-shaped muscle that works to open your lungs when you breathe. 

From your nose and mouth, air travels towards your lungs through a series of tubes.  The trachea or windpipe is located in your throat.  The bottom of the trachea separates into two large tubes called the main stem bronchi.  The left main stem bronchus goes into the left lung, and the right main stem bronchus goes into the right lung.

Inside the lung, the bronchi branch off and become smaller.  These smaller air tubes are called bronchioles.  There are approximately 30,000 bronchioles in each lung.  The end of each bronchiole has tiny air sacs called alveoli.  There are about 600 million alveoli in your lungs.  Each alveolus is covered in small blood vessels called capillaries.  The capillaries move oxygen and carbon dioxide in and out of your blood.

When you breathe air in or inhale, your diaphragm flattens and your ribs move outward to allow your lungs to expand.  The air that you inhale through your nose or mouth travels down the trachea.  Tiny hair like structures in the trachea, called cilia, filter the air to help keep mucus and dirt out of your lungs.  The air travels through the bronchi and the bronchioles and into the alveoli.  Oxygen in the air passes through the alveoli into the capillaries.  The oxygen attaches to red blood cells and travels to the heart.  The heart sends the oxygenated blood to the cells in your body.

When you breathe air out or exhale, the process is the opposite of when you inhale. Once your body has used the oxygen in the blood, the deoxygenated blood returns to the capillaries.  The blood now contains carbon dioxide and waste products that must be removed from your body.  The capillaries transfer the carbon dioxide and wastes from the blood into the alveoli.  The air travels through the bronchioles, the bronchi, and the trachea. As you exhale, your diaphragm rises and your ribs move inward.  As your lungs compress, the carbon dioxide is released out of your mouth or nose.

Bronchitis results from irritation or an infection that causes the trachea or large and small bronchi to become inflamed.  Acute bronchitis most commonly develops after a viral upper respiratory infection.  It occurs more frequently during flu season.  Cigarette smoking, air pollution, and allergies also cause irritation and can contribute to bronchitis.  Dust, chemicals, and fumes associated with certain occupations, such as coal mining, grain handling, and textile manufacturing, can cause bronchitis.

 

A common complication of bronchitis is the development of a second infection in the airways and lungs.  Bronchitis can lead to bacterial infections, including pneumonia.  Bronchitis can become a chronic condition.  Chronic bronchitis is categorized as a type of chronic obstructive pulmonary disease (COPD). 

Upper respiratory infections commonly precede bronchitis.  The infection typically infects the nose, sinuses, and throat before spreading to your lungs.  Bronchitis causes coughing.  You may cough very hard.  Coughing may cause discomfort in your chest.  Your cough may be dry or produce phlegm.  You may have a dry lingering cough for weeks after your case of bronchitis has resolved.

 

Bronchitis can cause shortness of breath.  Exercise or exertion can cause breathing symptoms to become worse.  Bronchitis can cause wheezing noises when you breathe.  You may also experience nasal congestion.

Bronchitis can make you feel tired all of the time.  You may have a low fever, chills, and muscle aches.  You may develop ankle, leg, and foot swelling.

 

Bronchitis can be acute or chronic.  Acute bronchitis usually resolves in 7 to 10 days, although a dry hacking cough can linger for weeks.  Chronic bronchitis is a long-term condition.  Bronchitis is diagnosed as chronic if you have a cough with mucus for most days in a three-month period in at least 2 consecutive years.  As chronic bronchitis gets worse, you will have more trouble breathing and staying active.

Most cases of acute bronchitis clear up on their own.  You should see your doctor if you have severe coughing, wheezing, difficult breathing, or a fever that lasts more than four or five days.

You doctor can usually diagnose bronchitis by simply reviewing your medical history and conducting a physical exam.  You should tell your doctor about your symptoms and risk factors.

Your doctor will listen to hear if your lungs make sounds when you breathe.  Your doctor may order tests to detect infection, determine the extent of your condition, and rule out other conditions that have similar symptoms.  Your doctor may use a pulse oximeter to determine the amount of oxygen in your blood.  For this test, a probe is simply placed on your fingertip and a reading is sent to a monitor.  Your doctor may check a sample of your phlegm for bacteria.  If your doctor suspects that you have pneumonia, a chest X-ray will be ordered. 

Acute bronchitis usually resolves on its own in about one week.  You should rest and drink plenty of fluids.  It may be helpful to use a cool mist vaporizer or humidifier.  Antibiotics do not work on viruses.  Over-the-counter medications can help suppress coughing and loosen secretions.  If your symptoms do not improve, your doctor can prescribe an inhaler to help you breathe easier and antibiotics if you develop a bacterial infection.

If you have chronic bronchitis, your doctor can recommend a respiratory therapy program for breathing exercises and physical activity.  Your doctor can prescribe inhaler medications to help you breathe.  You may need to use oxygen. 

Developing a secondary infection, such as pneumonia, is a risk with acute bronchitis.  There is also a small risk for acute bronchitis to turn into chronic bronchitis.