What Causes It?
Acute bronchitis is generally caused by lung infections; approximately 90% of these infections are viral in origin, 10% bacterial. Chronic bronchitis may be caused by one or several factors. Repeated attacks of acute bronchitis, which weaken and irritate bronchial airways over time, can result in chronic bronchitis.

Industrial pollution is another culprit. Chronic bronchitis is found in higher–than–normal rates among coal miners, grain handlers, metal molders, and other people who are continually exposed to dust. But the chief cause is heavy, long–term cigarette smoking, which irritates the bronchial tubes and causes them to produce excess mucus. The symptoms of chronic bronchitis are also worsened by high concentrations of sulfur dioxide and other pollutants in the atmosphere.

When a Cold Becomes Bronchitis?
When you catch a cold, does it often turn into bronchitis, which is sometimes called a chest cold? It’s important to recognize what’s normal and to know when something more serious is going on. Here’s what you must know when that nasty cold turns into bronchitis.

Should I Call My Doctor About a Cough?
A cough is a common cold symptom. It’s the body’s way of getting rid of phlegm or mucus. But if a cough persists after the cold is gone, contact your doctor.

It is helpful to tell your doctor how long you’ve had the cough. You also should tell the doctor whether any activities or exposures seem to make it worse, if you notice any other different or unusual feelings, and if you cough up mucus.

If you are coughing up thick green or yellow phlegm, or if you are wheezing, running a fever higher than 101° F, having night sweats, or coughing up blood, you need to see a doctor. These may be signs of a more serious illness that needs to be diagnosed and treated.

A persistent cough may be a sign of asthma. Sometimes this condition is called “Cough–variant asthma”. Cough–variant asthma is vastly under diagnosed and under treated. Triggers for cough–variant asthma are usually respiratory infections like a cold or flu. You may even have cough–variant asthma and think the cough is due to an allergy. Until an asthma attack occurs, you may not realize that your lungs are involved.

What is bronchitis (chest cold)?
Bronchitis occurs when the airways in your lungs are inflamed and make too much mucus. There are two basic types of bronchitis:
Acute bronchitis is more common and usually is caused by a viral infection. Acute bronchitis may also be called a chest cold. Episodes of acute bronchitis can be related to and made worse by smoking. This type of bronchitis is often described as being worse than a regular cold but not as bad as pneumonia.

Chronic bronchitis is a cough that persists for two to three months each year for at least two years. Smoking is the most common cause of chronic bronchitis.