Acute Bronchitis vs. Chronic Bronchitis

The bronchial tree is a complex system of passageways that most people don't think about until it becomes inflamed or filled with mucus—a condition generally called bronchitis. Bronchitis can be acute (coming on suddenly)—sometimes referred to as a chest cold—or chronic (continuing or recurring). Symptoms for each are similar, but how each develops and the impact each has on your health are different.

To understand the difference between acute and chronic bronchitis, it's important to understand how the bronchial tree works. While lungs get a lot of credit for helping us breathe, the bronchi serve as the functional passageway for air to travel from the mouth into the body and back out of the body again.

After you breathe air in through your nose and mouth, the air travels down the trachea (also called a windpipe)—the tube in the throat that carries air to the bronchi. The bronchi then pass that air into the left and right branches of the bronchial tree and, in turn, into the left and right lungs, where it moves through a series of smaller passageways: lobar bronchi, segmental bronchi, terminal bronchioles, and finally respiratory bronchioles.

At the end of each respiratory bronchiole is a tiny and delicate pocket called alveoli. This is where oxygen and carbon dioxide are carried to and from the lungs by capillaries. The alveoli and capillaries exchange the oxygen and carbon dioxide, with the bronchioles carrying carbon dioxide out as you exhale and the capillaries delivering fresh oxygenated blood to the rest of your body.

Chronic Bronchitis

Chronic bronchitis is one of the two primary types of chronic obstructive pulmonary disease (COPD). The other is emphysema, which occurs when the alveoli are damaged and can no longer exchange oxygen effectively, causing shortness of breath. Whereas emphysema affects the alveoli, chronic bronchitis is irritation and inflammation of the bronchial tubes that make it difficult to breathe.

The term "chronic" is given to this form of bronchitis because it can cause an ongoing cough that lasts for several months or even years. The cough is usually productive, meaning it brings up mucus. In chronic bronchitis, the lining of the airways is constantly inflamed, causing the lining to swell and produce more mucus, which can make it hard to breathe.

One study estimates that chronic bronchitis affects about 10 million people in the United States, most of whom are between 44 and 65 years old.

The risk factors of chronic bronchitis include:

• Smoking
• Long-term exposure to chemicals or irritants
• Being age 40 or older
• Genetics or family history of COPD
• Asthma
• A history of childhood respiratory diseases
• Allergies
• Gastroesophageal reflux disease (GERD)

Mucus production is the most common symptom of chronic bronchitis. Other symptoms include:

• Chest pain
• Wheezing
• Shortness of breath, especially with activity
• Low fever

Acute Bronchitis

Acute bronchitis causes the same inflammation and irritation as chronic bronchitis, but acute bronchitis is short term. Viral infections, such as the cold or flu, are usually the cause of acute bronchitis. Occasionally, acute bronchitis is due to a bacterial infection.

The most common viral causes of acute bronchitis include:

• Rhinovirus, the cause of the common cold
• Adenovirus, which causes cold-like symptoms, pneumonia, and diarrhea
• Influenza A, a common cause of the flu
• Influenza B, also a common cause of the flu
• Human parainfluenza viruses, which often leads to respiratory illnesses in children
• Respiratory syncytial virus, the most common cause of bronchiolitis and pneumonia in children under 1 year old

Bacteria that can cause acute bronchitis—especially in people with other health problems—include:

• Mycoplasma pneumoniae, which can cause tracheobronchitis (chest cold) or "walking pneumonia"
• Streptococcus pneumoniae, which can lead to middle ear infections, meningitis, and sinus infections
• Haemophilus influenzae, a cause of ear infections and bloodstream infections
• Moraxella catarrhalis, resulting in middle ear and sinus infections in children
• Bordetella pertussis, which causes whooping cough (pertussis)
• Staphylococcus aureus, which can lead to skin infections, pneumonia, and infection of the heart valves

An infection that causes acute bronchitis may clear in just a few days, but the cough that results from the irritation that has developed can last for weeks.

Symptoms of acute bronchitis include:

• Coughing, with or without bringing up mucus
• Fatigue, or a feeling of tiredness even after sleep
• Pain, tightness, or soreness in the chest
• Headaches
• Body or muscle aches
• Low-grade fevers
• Nasal congestion
• Sore throat

At-Risk Groups

There are some people who are at greater risk of both acute and chronic bronchitis than others. Smoking is a big risk factor for both forms of bronchitis, particularly chronic bronchitis (as well as the other primary form of COPD, emphysema). Previous injuries to the lungs from childhood respiratory diseases, asthma, or allergies can also make you more susceptible to both acute and chronic bronchitis. People who work with airborne chemicals or dusts for long periods of time are also at a higher risk of developing either form of bronchitis.

The risk of chronic bronchitis increases with age, and it is more common in women than in men.

Diagnosis

To diagnose bronchitis, your healthcare provider will ask you questions about your cough and general health. Examples of questions your healthcare provider may ask include:

• How long have you been coughing?
• When you cough, what kind of mucus are you bringing up?
• What other symptoms do you have?
• Have you had any recent colds or infections?
• Do you smoke?
• Where do you work and what exposure do you have to irritants or pollutants?
• What is your personal and family medical history?

To diagnose your bronchitis as chronic, your healthcare provider will usually look for a cough that lasts longer than three months as well as if you have a history of frequent bouts with acute bronchitis over a period of two years.

Tests

At first, your healthcare provider may use a stethoscope to listen to your lungs to confirm a diagnosis of bronchitis. Additionally, your healthcare provider may also order tests to learn more about your bronchitis—or rule out other problems, including:

• A chest X-ray
• A computed tomography (CT) scan
• A measurement of the oxygen levels in your blood (pulse oximetry)
• Blood tests for more precise measurements of the oxygen and carbon dioxide in your body (arterial blood gas)
• Lung function tests
• Complete blood count and other blood tests
• Microbiology tests—usually using mucus or sputum—to confirm virus or bacteria type

Treatment

Treatment of bronchitis depends on whether you have acute or chronic inflammation. Acute bronchitis usually goes away on its own without needing treatment. Even when bacteria are the cause of bronchitis, there is little evidence supporting the use of antibiotics. Instead, treatment for acute bronchitis focuses on managing your symptoms using the following medications:

• Over-the-counter cold medications to help loosen and expel mucus
• Humidifiers or cold-mist vaporizers
• Nonsteroidal anti-inflammatory drugs like ibuprofen to reduce inflammation and pain

Other things you can do to alleviate your symptoms include:

• Get lots of rest
• Stay hydrated
• Use honey or lozenges to relieve throat pain

For chronic bronchitis, symptom management is also key, but for different reasons. Chronic bronchitis has no cure, but reducing risk factors and avoiding triggers can help prevent flare-ups. Quitting smoking is a major step toward treating chronic bronchitis. Other treatments that might provide relief include:

• Oxygen therapy
• Bronchodilators
• Steroids
• Pulmonary rehabilitation therapy
• Breathing exercises

A Word From Verywell

Acute bronchitis can be painful but passes fairly quickly. If you suffer from repeat episodes of bronchitis or have been diagnosed with chronic bronchitis, just remember that you can still achieve good quality of life. Proper management and a change in lifestyle like quitting smoking can help you avoid exacerbations and may even help prevent further damage to your lungs. Chronic bronchitis can't be cured, but it can be managed with the proper diagnosis and treatment.