Definition

Just when you thought you were finally over a cold, your chest starts to feel sore and you develop a cough. Later, you might get the chills or a slight fever.

If these signs and symptoms sound familiar, you might have acute bronchitis, a condition that occurs when the inner walls that line the main air passageways of your lungs become infected and inflamed. Bronchitis often follows a respiratory infection such as a cold. Smoking and exposure to smoke are also risk factors for bronchitis.

Most cases of acute bronchitis disappear within a few days without lasting effects, although coughs may linger for weeks. If you have repeated bouts of bronchitis, see your doctor. You may have a more serious health problem — such as asthma or chronic bronchitis — that needs medical attention.

Symptoms

A cough that brings up yellowish-gray or green mucus (sputum) is one of the main signs of bronchitis. Mucus itself isn't abnormal — your airways normally produce up to several tablespoons of mucus secretions every day. But these secretions usually don't accumulate, because they're continuously cleared into your throat and swallowed with your saliva.

When the main air passageways in your lungs (bronchial tubes) are inflamed, they often produce large amounts of discolored mucus that comes up when you cough. If this persists for more than three months, it is referred to as chronic bronchitis. Mucus that isn't white or clear usually means there's a secondary infection.

Still, 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. Many smokers have to clear their throat every morning when they get up. While they may think this is normal for everyone, it's not. If it continues for more than three months, it may be chronic bronchitis.

Accompanying symptoms of an upper respiratory infection
Acute bronchitis also may be accompanied by common signs and symptoms of an upper respiratory infection, including:

• Soreness and a feeling of constriction or burning in your chest
• Sore throat
• Chest congestion
• Sinus fullness
• Breathlessness
• Wheezing
• Slight fever and chills
• Overall malaise

Sometimes chronic sinusitis — an ongoing infection in the lining of one or more of the cavities in the bone around your nose — can mimic bronchitis. That's because the signs and symptoms of chronic sinusitis include a thick, yellow or green postnasal discharge and a chronic cough that's triggered when you try to clear your throat of mucus draining from your sinuses, instead of your lungs, as is the case with bronchitis.

Causes

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 cigarette smoke and even from pollutants such as household cleaners and smog.

Bronchitis may also occur when acids from your stomach consistently back up into your food pipe, 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. Signs and symptoms include shortness of breath and a continual cough that produces large amounts of mucus. 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. In some people, chronic inflammation of the airways may lead to asthma.

Risk factors

People who smoke or who live with a smoker are at greatest risk of both acute and chronic bronchitis. Children whose parents or siblings smoke also are susceptible to bronchitis, as well as to asthma, pneumonia, colds and ear infections (otitis media).

Other factors that increase your risk of bronchitis include:

• 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 also have greater vulnerability to infection.
• Gastroesophageal reflux disease (GERD). Stomach acids that persistently back up into your esophagus may cause a chronic cough, usually through a reflex mechanism.
• Exposure to certain 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.

When to seek medical advice

Most cases of bronchitis clear on their own in a few days, especially if you rest, drink plenty of fluids, avoid exposure to tobacco smoke and keep the air in your home warm and moist.

Call your doctor if:

• Your cough is severe or is preventing you from sleeping. He or she may recommend prescription cough suppressants to help you get some rest.
• You have a low-grade fever that persists more than three days or a fever higher than 101 F, you're breathless, or you cough up bloody or yellow or green mucus, see your doctor. You may have pneumonia. And if you have a cough that lasts more than three weeks, be sure to seek medical care. The inflammation from a chronic infection may 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 a case of 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 you may live or work in an environment that continually irritates your airways. In some cases, you may have GERD or chronic sinusitis. If so, your doctor may be able to pinpoint the cause of your problem and suggest further testing and lifestyle changes that can help.

Tests and diagnosis

To diagnose bronchitis, your doctor will likely listen to your chest with a stethoscope. You may also be asked to have a chest X-ray and perhaps a sputum culture — a test that checks for the presence of bacteria in sputum produced when you cough.

In some cases your doctor may recommend additional tests to rule out other causes for your symptoms, including a pulmonary function test (PFT) that checks for signs of asthma or emphysema. During a PFT, you blow into a device called a spirometer, which measures the volume of air in your lungs after you've taken a deep breath and blown it out. The spirometer also shows how quickly you can get air into your lungs. The test is painless and takes just a few minutes. If you have repeated bouts of bronchitis and your doctor doesn't suggest a PFT, ask to have one done.

Complications

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 this complication.

Take repeated bouts of bronchitis seriously. They may signal chronic bronchitis, asthma or other lung disorders. Also, if you have chronic bronchitis and you continue to smoke you're at increased risk of lung cancer — over and above the normal risk that smokers face.

Treatments and drugs

Antibiotics don't effectively treat most cases of bronchitis because the condition usually results from a viral infection. Instead, the following are the cornerstones of acute bronchitis treatment:

• Get plenty of rest.
• Drink extra liquids.
• Take a nonprescription cough medicine.

It's best not to suppress a cough that brings up mucus, however, because coughing helps remove irritants from your lungs and air passages. If your cough is keeping you awake at night, use just enough cough medicine so that you can rest, but not enough to suppress your cough completely. There are several kinds of over-the-counter (OTC) cough medicines. Read their labels to figure out which is most likely to relieve the type of cough you have. If your cough is preventing you from sleeping, your doctor may recommend a prescription cough suppressant.

Your doctor may prescribe an antibiotic if he or she suspects that you have a bacterial infection. If you have a chronic lung disorder or if you smoke, your doctor may also prescribe antibiotics to reduce your risk of a serious, secondary infection.

If you have asthma, your doctor may recommend an inhaler and other asthma medications to reduce inflammation and open narrowed passages in your lungs.

Prevention

If you have frequent, repeated attacks of bronchitis, the culprit may be something in your environment. Cold, damp locations — especially in combination with air pollution or tobacco smoke — can make you more susceptible to acute bronchitis. When the problem is severe, you may need to consider changing where and how you live and work.

These measures also may help prevent bronchitis and protect your lungs in general:

• Avoid smoking and exposure to secondhand smoke. Tobacco smoke increases your risk of chronic bronchitis and emphysema.
• Get an annual flu vaccine. Many cases of acute bronchitis result from influenza. Getting a yearly flu vaccine can help protect you from getting the flu, which in turn, may reduce your risk of bronchitis.
• Ask your doctor about a pneumonia shot. If you're older than 65 or you have risk factors such as diabetes, heart disease and emphysema, consider having a pneumonia shot. In addition, a vaccine known as Prevnar can help protect young children against pneumonia. It's recommended for all children under age 2 and for children 2 to 5 years old who are at particular risk of pneumococcal disease, such as those with an immune system deficiency, asthma, cardiovascular disease or sickle cell anemia. Side effects of the pneumococcal vaccine are generally minor and include mild soreness or swelling at the injection site.
• Use hand sanitizers regularly. To reduce your risk of catching a viral infection, get in the habit of using hand sanitizers, and don't touch the inside of your nose or rub your eyes.
• When practical, wear a face mask. If you have to spend a lot of time around other people who are coughing and sneezing, it's a good idea to wear a face mask to reduce your risk of infection.

Lifestyle and home remedies

Besides the basic treatments of rest, liquids and over-the-counter cough medications, these suggestions can help make you more comfortable, speed recovery and prevent complications of acute bronchitis:

• Use a humidifier in your room. Warm, moist air helps relieve coughs and loosens mucus in your airways. But be sure to clean the humidifier according to the manufacturer's recommendations to avoid the growth of bacteria and fungi in the water container.
• Use over-the-counter medications. To relieve pain and lower a high fever, acetaminophen (Tylenol, others) and ibuprofen (Advil, Motrin, others) may help. Adults may also use aspirin. But don't give aspirin to children. It may trigger a rare, but potentially fatal, disorder known as Reye's syndrome.
• Avoid exposure to irritants, such as tobacco smoke. Wear a mask when the air is

By Mayo Clinic Staff
April 20, 2007