Bronchitis is an inflammation of the lining of your bronchial tubes, which carry air to and from your lungs. Bronchitis may be either acute or chronic.

A common condition, acute bronchitis often develops from a cold or other respiratory infection. Chronic bronchitis, a more serious condition, is a constant irritation or inflammation of the lining of the bronchial tubes, often due to smoking.  

Acute bronchitis usually improves within a few days without lasting effects, although you may continue to cough for weeks. However, if you have repeated bouts of bronchitis, you may have chronic bronchitis, which requires medical attention. Chronic bronchitis is one of the conditions included in chronic obstructive pulmonary disease (COPD).

Treatment for bronchitis focuses on relieving your symptoms and easing your breathing.

For either acute bronchitis or chronic bronchitis, signs and symptoms may include:

• Cough
• Production of mucus (sputum), either clear or white or yellowish-gray or green in color
• Shortness of breath, made worse by mild exertion
• Wheezing
• Fatigue
• Slight fever and chills
• Chest discomfort

If you have acute bronchitis, you may have a nagging cough that lingers for several weeks after the bronchitis resolves. However, bronchitis symptoms can be deceptive. You don’t always produce sputum when you have bronchitis, and children often swallow coughed-up material, so parents may not know there’s a secondary infection. You can develop chronic bronchitis without first developing acute bronchitis. And many smokers have to clear their throats every morning when they get up, which, if it continues for more than three months, may be chronic bronchitis.

Symptoms of chronic bronchitis
If you have chronic bronchitis, long-term inflammation leads to scarring of the bronchial tubes, producing excessive mucus. Over time, the lining of the bronchial tubes thickens, and your airways eventually may become scarred. Signs and symptoms of chronic bronchitis may also include:

• Cough that’s worse in the mornings and in damp weather
• Frequent respiratory infections (such as colds or the flu) with a worsening productive cough

If you have chronic bronchitis, you’re likely to have periods when your signs and symptoms worsen. At those times, you may have superimposed acute bronchitis, either viral or bacterial, in addition to chronic bronchitis.

When to see a doctor
Acute bronchitis usually resolves on its own in a few days. See your doctor if:

• Your cough is severe or prevents you from sleeping. Your doctor may recommend prescription cough suppressants to help you rest.
• You have a low-grade fever that persists more than three days or a fever higher than 101 F (38.3 C), you’re breathless, or you cough up bloody or yellow or green mucus. You may have pneumonia. Discolored mucus usually indicates a bacterial infection, which would respond to antibiotics. You also may have developed a bacterial sinusitis.
• Your cough lasts more than three weeks. The inflammation from a chronic infection can lead to asthma in some people.
• You have chronic lung or heart problems, including asthma, emphysema or congestive heart failure, and think you may have developed bronchitis. These conditions put you at greater risk of developing complications from bronchial infections.
• You have repeated bouts of bronchitis. You may have chronic bronchitis or another serious health condition, such as asthma or bronchiectasis, a stretching of the respiratory passages caused by mucus blockage.

Acute bronchitis
The same viruses that cause colds often cause acute bronchitis. But you can also develop noninfectious bronchitis from exposure to your own or someone else’s tobacco smoke and from pollutants such as household cleaners and smog.

Bronchitis may also occur when acids from your stomach consistently back up into your food pipe (esophagus) and a few drops go into your upper airway, a condition known as gastroesophageal reflux disease (GERD). And workers exposed to certain dusts or fumes may develop occupational bronchitis, an acute disease that generally clears up when exposure to the irritant stops.

Chronic bronchitis
Sometimes inflammation and thickening of the lining of your bronchial tubes become permanent — a condition known as chronic bronchitis. You’re generally considered to have chronic bronchitis if you cough most days for at least three months a year in two consecutive years. Often, however, smokers with chronic bronchitis cough almost every day, even if it’s just to “clear their throats” in the morning.

Unlike acute bronchitis, chronic bronchitis is an ongoing, serious disease. Smoking is the major cause, but air pollution and dust or toxic gases in the environment or workplace also can contribute to the condition.

Factors that increase your risk of bronchitis include:

• Cigarette smoke. People who smoke or who live with a smoker are at greatest risk of both acute bronchitis and chronic bronchitis. Children in households where someone smokes also are susceptible to bronchitis, as well as to asthma, pneumonia, colds and middle ear infections (otitis media).
• Low resistance. This may result from another acute illness, such as a cold, or from a chronic condition that compromises your immune system. Older adults, infants and young children have greater vulnerability to infection.
• Gastroesophageal reflux disease (GERD). Stomach acids that persistently back up into your esophagus may cause a chronic cough.
• Exposure to irritants on the job. You run the risk of developing occupational bronchitis if you work around certain lung irritants, such as grains or textiles, or are exposed to chemical fumes from ammonia, strong acids, chlorine, hydrogen sulfide, sulfur dioxide or bromine. The cough associated with occupational bronchitis may be dry (nonproductive). Occupational bronchitis usually clears up when you’re no longer exposed to these substances. This type of bronchitis isn’t related to any infectious agent, but the irritation of the airways makes you more susceptible to getting an infection.

A single episode of bronchitis
Although a single episode of bronchitis usually isn’t cause for concern, it can lead to pneumonia in some people. Older adults, infants, smokers and people with chronic respiratory disorders or heart problems are at greatest risk of getting pneumonia.

Repeated bronchitis
Take repeated bouts of bronchitis seriously. They may signal:

• Chronic bronchitis
• Asthma
• Other lung disorders

Also, if you have chronic bronchitis and you continue to smoke, your risk of lung cancer increases beyond the normal risk that smokers face.