Types of bronchitis
Bronchitis is a chest infection that affects the main airways of your lungs, the two bronchi. The walls of your lungs’ main airways produce mucus to trap unwanted invading pathogens and materials like dust that you breathe in to dispose of them properly. This defensive tool is turned against us in bronchitis infections, the airways become inflamed and irritated so producing more and more mucus. This causes the classic bronchitis symptoms of a persistent cough and chest aches as your body attempts to shift the thick excess mucus. Acute bronchitis is a transient chest infection that lasts up to 3 weeks in the lungs then should be fought off by your body’s natural immune defence.1 Chronic bronchitis is much more serious, it is a long-term condition classed as a chronic obstructive pulmonary disease (COPD). During chronic bronchitis, you experience bronchitis symptoms for around 3 months each year.
Usual causes of bronchitis
Bronchitis infections can be categorised by cause too. This condition can be brought on by a viral or bacterial infection in the lungs. Viral bronchitis is normally caused by a virus infiltrating the cells that line your bronchi, these are mostly the same viruses that cause common colds and flu that travel downwards to infect your lungs. Bacterial infections cause fewer amount of bronchitis cases. Viral and bacterial bronchitis infections are spread by an infected individual coughing or sneezing out pathogen-containing droplets. These can be inhaled or spread by touching surfaces where the infected droplets have landed so that the virus or bacteria can infiltrate the new host.2 Lastly, bronchitis, especially chronic bronchitis can be caused by no invading pathogen, but instead the inhalation of environmental irritants such as tobacco smoke and strong acids that will cause inflammation to the respiratory tracts.
Signs and symptoms
Bronchitis symptoms vary from patient to patient, these include:3
- a persistent chesty cough
- coughing up mucus (green/grey/yellow phlegm)
- a sore throat
- chest pains
- a blocked/runny nose
- a high temperature
- difficulty breathing, breathlessness, or shallow breathing
- muscle pain (tummy muscles can start to ache after coughing so much)
What does bronchitis sound like?
Determining the type of bronchitis based on its sound
Bronchitis is associated with a productive, raspy, chesty, wet cough. These characteristics are found due to the build-up of mucus in the lungs from airway wall irritation. Coughing is your body’s way of trying to shift the mucus. If you experience this combined with some of the other symptoms, you may have bronchitis. Upon visiting a doctor, when carrying out a physical examination of your lungs they will listen to your lungs through a stethoscope. Bronchitis will often appear as wheezing and crackles through the stethoscope.4 This examination is mostly to rule out more serious lung conditions like pneumonia (in which symptoms often overlap with those of bronchitis). Pneumonia, unlike bronchitis, is associated with Ronchi (a low-pitched ongoing lung sound), bronchial breath sounds (indicating fluid consolidating the lungs), crackles and wheezing.
Duration of the cough sounds is the best way to decipher which subtype of bronchitis a patient has. Acute bronchitis will have symptoms lasting up to three weeks, sometimes with the cough persisting for longer. Chronic bronchitis is a long-term condition that sees more severe coughing than acute bronchitis and for a longer period. Symptoms of breathlessness and wheezing in patients, altering the sound of their coughs, inhalations and exhalations are more common in chronic bronchitis so this could be an indicator of the disease subtype.5 This is because permanent damage to the lungs is caused by chronic bronchitis. Symptoms of bronchitis are similar depending on the cause, with bacterial and viral infections causing the same inflammation that produces the characteristic bronchitis wet cough. Therefore, to understand what infectious agent caused the condition, further investigation is needed. Some researchers hypothesise that grey-yellow phlegm means a viral infection and green phlegm produced shows a bacterial infection present. 90% of acute bronchitis cases are caused by a viral infection.6
How is bronchitis diagnosed?
To diagnose bronchitis, a healthcare professional will ask you questions surrounding your symptoms and how you feel and perform a physical exam to listen to your lungs. Further tests may need to be done to rule out a more serious lung condition such as pneumonia, these include running a lab test on your mucus sample and performing a chest x-ray.7
Pneumonia is the most common complication of bronchitis (with 5% of bronchitis patients developing it).8 This happens when the infectious agent spreads further down your lungs causing more damage. While walking pneumonia (less severe) can be treated without proper intervention, pneumonia should be monitored because it can often lead to serious problems for the patient. People more at risk of developing pneumonia are people with weaker immune systems or lungs. This includes the elderly, smokers and those with existing health conditions.
Chronic bronchitis is the severe and ongoing inflammation of the lungs to cause multiple prolonged bronchitis episode per year. Having chronic bronchitis causes lung damage and increases the likelihood of complications such as death. Due to your lungs being weakened by this chronic condition, you are more likely to catch other respiratory infections such as colds, the flu and pneumonia, and find it difficult to fight them off. Smoking is the number one risk factor for chronic bronchitis, so to ameliorate complication risk, it is aggressively recommended that you quit smoking to reduce the burden on the lungs. Emphysema is a complication of chronic bronchitis, especially if it was caused by smoking. Emphysema causes difficulty breathing because it occurs when the air sacs in the lungs are permanently damaged.9
Treatment and prevention of bronchitis
Acute bronchitis cases usually go away on their own without medical intervention, with proper rest and care. You can make a hot honey and lemon drink to soothe your sore throat. It is important to drink lots of fluids so the thick mucus clogging up your lungs thins.
Lead a healthy lifestyle by improving your dietary and exercise habits and quitting smoking. This will increase your pulmonary health and boost your immune system to fight off chest infections. To avoid bronchitis infections after the flu, you can register to get the yearly flu vaccine for free on the NHS. This is especially recommended if you are elderly, immunocompromised, or have a pre-existing health condition.
At home, paracetamol and ibuprofen are recommended to manage bronchitis symptoms. In chronic bronchitis patients, steroids can be prescribed to open up the airways to reduce the mucous burden on the lungs. Mucolytic drugs can alternatively be administered, these medicines break down the mucous in the lungs, thinning it and making it easier to shift. Most bronchitis cases are caused by a virus. Antibiotics do not destroy viruses so they are not prescribed to bronchitis patients unless sure the condition is caused by a bacterial infection or to limit the possibility of pneumonia forming in at-risk individuals.10
When to seek medical attention
Most bronchitis cases will pass with at-home rest, pain killers and increased fluid intake. However, if your symptoms get worse it is wise to contact your GP for advice.
Seek medical attention if:
- The mucous you cough up has blood in it
- Your fever (high temperature) lasts for over 3 days
- Your breathlessness is getting worse
- You have suffered multiple cases of bronchitis
- Your bronchitis symptoms last over 3 weeks
Most bronchitis cases are easily remedied at home with plenty of rest and fluid. However, it is important to know if your chest infection is something more sinister. That is why it is important to be able to distinguish between bronchitis and other lung conditions as well as differentiate between the different subtypes of bronchitis. This way doctors will be able to diagnose and treat you earlier, giving you the best possible chance to get past your illness.
- Reid LM. Pathology of chronic bronchitis. Lancet. 1954:275-8.
- Gonzales R, Sande MA. Uncomplicated acute bronchitis. Annals of internal medicine. 2000 Dec 19;133(12):981-91.
- Oeffinger KC, Snell LM, Foster BM, Panico KG, Archer RD. Diagnosis of acute bronchitis in adults: a national survey of family physicians. Journal of family practice. 1997 Nov 1;45(5):402-9.
- Forgacs P, Nathoo AR, Richardson HD. Breath sounds. Thorax. 1971 May 1;26(3):288-95.
- Kinkade S, Long NA. Acute bronchitis. American family physician. 2016 Oct 1;94(7):560-5.
- Albert RH. Diagnosis and treatment of acute bronchitis. American family physician. 2010 Dec 1;82(11):1345-50. https://www.nhs.uk/conditions/bronchitis/#:~:text=Pneumonia%20is%20the%20most%20common,of%20bronchitis%20lead%20to%20pneumonia.
- Forey BA, Thornton AJ, Lee PN. Systematic review with meta-analysis of the epidemiological evidence relating smoking to COPD, chronic bronchitis and emphysema. BMC pulmonary medicine. 2011 Dec;11(1):1-61.
- Woodhead M, Blasi F, Ewig S, Garau J, Huchon G, Ieven M, Ortqvist A, Schaberg T, Torres A, Van Der Heijden G, Read R. Guidelines for the management of adult lower respiratory tract infections‐Full version. Clinical microbiology and infection. 2011 Nov;17:E1-59.