Bronchitis
Flu complication: Bronchitis
The most common complication of the flu, bronchitis is an infection of the main airways of your lungs.
It makes them irritated and inflamed and causes them to produce more mucus. Your body tries to shift this extra mucus through coughing.
In most cases, bronchitis is caused by the same viruses that cause a cold or the flu.
Treatment (3)
Acute (temporary) bronchitis will clear up by itself within a few weeks without the need for treatment in most cases.
In the meantime, drink lots of fluid and get plenty of rest.
Your doctor may prescribe antibiotics if you have an increased risk of developing further complications, such as pneumonia.
Impact if untreated (3)
Your cough may last for several weeks after other symptoms have gone, and you may also find that the continual coughing makes your chest and stomach muscles sore.
About 1 in 20 cases of bronchitis lead to pneumonia.
You are at greater risk if you are elderly, a smoker or have other health conditions or a weakened immune system.
Sources
(1) https://ecdc.europa.eu/en/seasonal-influenza/facts/questions-and-answers-seasonal-influenza
(2) http://www.nhs.uk/Conditions/Flu/Pages/Complications.aspx
(3) http://www.nhs.uk/conditions/Bronchitis/Pages/Introduction.aspx