RELATED STORIES • Acute bronchitis: Is it contagious? ASTHMA & RESPIRATORY SYSTEM Emphysema • Bronchitis • Pneumonia • Pleurisy • Sarcoidosis • Cystic fibrosis • Emphysema • Respiratory syncytial virus • Pulmonary embolism • Bronchiolitis • Asbestosis • Interstitial lung disease ASTHMA & RESPIRATORY SYSTEM Respiratory System • Bronchitis • Pneumonia • Pleurisy • Respiratory syncytial virus • Bronchiolitis

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Just when you thought you were finally over a cold, your chest starts to feel sore and you develop an irritating 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. And just as most people get occasional colds, virtually everyone has bronchitis at least once.

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

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 produce at least an ounce of normal 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, however, they often produce large amounts of discolored mucus that comes up when you cough. Mucus that isn't white or clear usually means there's a secondary infection.

Still, these signs 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.

Bronchitis 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
• Congestion
• 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.

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 can also occur when acids from your stomach consistently back up into your food pipe, a condition known as gastroesophageal reflux disease, or 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.

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 leads to asthma.

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 are especially 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. Stomach acids that persistently back up into your esophagus are likely to 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 flax, hemp or cotton dust, 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.

Most cases of bronchitis clear on their own in a few days, especially if you rest, drink plenty of fluids, and keep the air in your home warm and moist. If your cough is severe or is preventing you from sleeping, call your doctor. He or she may recommend prescription cough suppressants to help you get some rest.

If you have a low-grade fever that lasts 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 six weeks or more, be sure to seek medical care. The inflammation from a chronic infection can lead to asthma in some people.

Also see your doctor if 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.

If you have repeated bouts of bronchitis, tell your doctor. 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.

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.

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.

Repeated bouts of bronchitis should be taken seriously. They may signal chronic bronchitis, asthma or other lung disorders. Having chronic bronchitis also increases your risk of lung cancer if you're a smoker or if you're exposed to someone else's tobacco smoke over a long period of time.

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 treatment for acute bronchitis:

• 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.

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 both bronchitis and the flu.
• Ask your doctor about a pneumonia shot. If you're older than 55 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 years and older 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.

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 OTC medications to relieve pain and lower a very high fever. These medications may include acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin, others). 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 polluted, or if you're exposed to irritants at work.