What is acute bronchitis?

Acute bronchitis is an infection of the lining of the bronchial tree that transports air into the lungs. ‘Acute’ means that the condition can develop very quickly and symptoms will occur for a short amount of time. An acute bronchitis infection can occur in adults or children and involves viruses or bacteria attacking the wall of the large airways (bronchi). The bronchial wall becomes swollen and produces mucus. Blood vessels in the bronchial wall widen as they become inflamed and white blood cells are transported to the site of infection. The body will then be able to destroy viruses and bacteria. The natural course of acute bronchitis takes between one and four weeks to complete. Patients with no other medical problems normally recover well and often with no specific treatment.

What are the symptoms of acute bronchitis?

• Coughing
• Coughing up mucus
• Fever (sometimes)
• Shortness of breath (sometimes)

What is coughing and why does it happen?

Coughing is a reaction that is triggered by an infection or irritation in the airways. When the airways get infected or irritated, the walls of the airways become inflamed and release mucus and dead cells. This stimulates small nerves in the airways and makes you cough.

Coughing consists of three steps:

1) A deep breath in

2) The throat closes and muscles between the ribs and in the stomach wall contract

3) The throat opens to rapidly release the trapped air

Coughing is a normal and important reflex that helps protect the lungs by clearing mucus and other material from your airways. It can occur as part of a common cold or sore throat but can take up to a month to completely stop. However, if you develop an unexplained cough that gradually gets worse or lasts for longer than 3-4 weeks, you should ask your doctor for advice.

What makes you cough?

• Acute bronchitis (either viral or bacterial)
• Chronic obstructive pulmonary disease (COPD)
• Asthma
• Pneumonia
• Lung tumours
• Acid reflux (acid in the stomach rising into the oesophagus)
• ACE inhibitors (drugs used to lower blood pressure)
• Choking, caused by a foreign object in the airway
• Fluid on the lung (which may cause shortness of breath)

What other problems can acute bronchitis cause?

• Difficulty in carrying out daily activities, such as going to school or work, or playing sport
• Interrupted sleep due to coughing
• Incontinence due to the stress of coughing

What is the relationship between acute bronchitis, asthma and pneumonia?

• Acute bronchitis is a viral or bacterial infection of the airways (bronchi)
• Asthma is an inflammation of the airways, which occurs in susceptible people and may be triggered by allergy, cold air, irritant chemicals or viral infections of the nose, throat and airways
• Pneumonia is a bacterial infection of the lungs that can occur either in one specific area (lobar pneumonia) or throughout the lungs (bronchopneumonia). Certain symptoms, like shortness of breath, fever, specific signs when listening to your lungs and low blood pressure, will help your doctor decide whether you have pneumonia instead of acute bronchitis. If your doctor is concerned, they may suggest that you have a chest X-ray, which is the best way to check for pneumonia.

How long will acute bronchitis last?

Uncomplicated cases usually ease within a few weeks and do not need treatment from a doctor. When a cough lasts for longer than 4 weeks, your doctor may want to check for underlying conditions or complications such as COPD or lung cancer, especially if you smoke, or tuberculosis (TB) if you live in a high-risk TB area.

How can acute bronchitis be treated?

Most cases of acute bronchitis will improve without specific treatment. You may be advised to play less sport to stop you from coughing, to avoid crowds and to wash your hands regularly to prevent the spread of infection. However, you may need antibiotics if your doctor suspects severe bacterial infection. This will reduce the infection and the risk of complications. A course of antibiotics of between five and seven days is usually enough to improve symptoms. Before prescribing antibiotics, your doctor will consider your age (particularly if under 6 months or over 75 years), the presence of fever or shortness of breath, any specific finings when listening to your lungs with a stethoscope, and whether you have other chronic conditions such as asthma, diabetes, COPD or heart failure. Cough syrups and suppressants are used widely to help soothe the throat but probably do not help very much. It is also important that you drink enough water to prevent getting dehydrated.

GRACE is an EU 6th Framework Programme Network of Excellence to combat resistance to antibiotics in the community. This project aims to combine the activities of physicians and scientists from many institutions in 14 European countries to combat antibiotic resistance in community-acquired lower respiratory tract infections.

This information was compiled by ERS expert, Prof. Theo Verheij.