Acute Bronchitis

Acute bronchitis is caused by infection due to

Bronchitis occurs most often during the winter.

Viral bronchitis may be caused by a number of common viruses, including the influenza virus Influenza (Flu) Influenza (flu) is a viral infection of the lungs and airways with one of the influenza viruses. It causes a fever, runny nose, sore throat, cough, headache, muscle aches (myalgias), and a general... read more and the viruses that cause the common cold Common Cold The common cold is a viral infection of the lining of the nose, sinuses, and throat. Many different viruses cause colds. Usually, colds are spread when a person's hands come in contact with... read more . Acute bronchitis can also occur as part of the SARS-CoV-2 infection COVID-19 COVID-19 is an acute respiratory illness that can be severe and is caused by the coronavirus named SARS-CoV-2. Symptoms of COVID-19 vary significantly. Two types of tests can be used to diagnose... read more . Even after a viral infection has cleared up, the irritation it causes can continue to cause symptoms for weeks.

Bacteria cause less than one in 20 cases of bronchitis. Mycoplasma pneumoniae Mycoplasmas Mycoplasmas are bacteria that cause infections in the respiratory tract and the urinary and genital tracts. Mycoplasmas are different from other bacteria because they do not have cell... read more , Chlamydia pneumoniae Chlamydia pneumoniae Chlamydia are bacteria that cause disease in humans, including sexually transmitted infections (STIs), and infections of the eyes and respiratory tract. Three species of Chlamydia... read more , and Bordetella pertussis infection (which causes whooping cough Pertussis Pertussis is a highly contagious infection caused by the gram-negative bacteria Bordetella pertussis, which results in fits of coughing that usually end in a prolonged, high-pitched,... read more ) are among the bacteria that cause acute bronchitis. Bacterial causes of acute bronchitis are more likely when many people in the same area are affected at the same time (an outbreak).

Cough in adults Cough in Adults Cough is a sudden, forceful expulsion of air from the lungs. It is one of the most common reasons people see a doctor. The function of a cough is to clear material from the airways and to protect... read more has many causes besides acute bronchitis. Cough in children Cough in Children Cough helps clear materials from the airways and prevent them from going to the lungs. The materials may be particles that have been inhaled or substances from the lungs and/or airways. Most... read more has similar causes as in adults.

Infections causing acute bronchitis typically begin with the symptoms of a common cold: runny nose, sore throat, and fatigue. In addition, in people with COVID-19, fever, muscle aches, gastrointestinal symptoms, and loss of smell and taste are more common.

After several days, cough begins (usually dry at first). People may cough up small amounts of thin, white mucus. This mucus often changes from white to green or yellow and becomes thicker. The color change does not indicate a bacterial infection. Color change means only that cells associated with inflammation have moved into the airway and are coloring the sputum.

People do not usually have a high fever or chills unless the bronchitis was caused by a more serious infection, such as influenza Influenza (Flu) Influenza (flu) is a viral infection of the lungs and airways with one of the influenza viruses. It causes a fever, runny nose, sore throat, cough, headache, muscle aches (myalgias), and a general... read more , or pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more has developed.

Because bronchitis can temporarily narrow the airways, people may develop wheezing and/or shortness of breath, similar to what happens in an asthma attack Asthma Asthma is a condition in which the airways narrow—usually reversibly—in response to certain stimuli. Coughing, wheezing, and shortness of breath that occur in response to specific triggers are... read more .

Acute bronchitis itself does not cause serious complications. However, the cough can last for 2 to 3 weeks or even longer. Some infections that cause bronchitis, such as influenza Influenza (Flu) Influenza (flu) is a viral infection of the lungs and airways with one of the influenza viruses. It causes a fever, runny nose, sore throat, cough, headache, muscle aches (myalgias), and a general... read more , can lead to infection of the lung tissue (pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more ), usually only in people who are older or who have problems with immune defenses Overview of the Immune System The immune system is designed to defend the body against foreign or dangerous invaders. Such invaders include Microorganisms (commonly called germs, such as bacteria, viruses, and fungi) Parasites... read more .

Doctors usually make a diagnosis of acute bronchitis based on the symptoms. Doctors may do a chest x-ray to look for pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more if they hear congestion in the lungs, or if people have high or prolonged fever or shortness of breath.

Doctors rarely do tests to find the cause of acute bronchitis, and blood tests are not helpful. However, testing for SARS-CoV2 may be done. Also, if a cough persists for more than 8 weeks, a chest x-ray is done to make sure that pneumonia has not developed or a different lung disease is not causing the cough.

People may take acetaminophen or ibuprofen to reduce fever and general feelings of illness and should drink plenty of fluid.

Antibiotics do not help viral bronchitis. Since most acute bronchitis is viral, doctors give antibiotics only when the infection is clearly caused by bacteria (for example, during an outbreak). When an antibiotic is used, doctors typically give a medication such as azithromycin or clarithromycin. Sometimes doctors prescribe antibiotics but recommend that they be used only if symptoms persist.

People who are wheezing may benefit from inhaled bronchodilators Treatment for a few days; however, side effects such as tremor, nervousness, and shaking can occur.

Cough medicines Cough suppressants Cough is a sudden, forceful expulsion of air from the lungs. It is one of the most common reasons people see a doctor. The function of a cough is to clear material from the airways and to protect... read more can be used to suppress a cough that is distressing or interferes with sleep. However, the degree of effectiveness of these medications is not clear. Expectorants are over-the-counter medications that may help thin secretions and make them easier to cough up, but whether this measure is helpful is not clear. Cough suppressants and expectorants are usually not recommended in young children (see also Cough in Children Cough in Children Cough helps clear materials from the airways and prevent them from going to the lungs. The materials may be particles that have been inhaled or substances from the lungs and/or airways. Most... read more ).