Bronchitis is an infection of the main airways of the lungs (bronchi), which causes them to become inflamed. It is common in winter and often develops following a cold, sore throat or flu
The main symptom of bronchitis is a cough, which may bring up yellow-grey mucus. Bronchitis may also cause a sore throat, wheezing and a blocked nose.
Who is affected?
Anyone can be affected by bronchitis, although smokers and people who work with substances that can irritate the lungs, such as grains or textiles, are more likely to get it.
Acute and chronic bronchitis
Bronchitis is usually a mild and self-limiting condition. Self-limiting means that it clears up by itself, usually within a couple of weeks. This is known as acute bronchitis as it lasts for only a short period of time.
However, in some cases, the damage caused by the infection of the bronchi can become permanent, causing the condition to be more severe and long lasting. If the infection lasts longer than three months, it is known as chronic bronchitis.
Most cases of bronchitis can be treated easily at home and do not usually require further medication. However, people with severe or chronic bronchitis, or those with an underlying condition such as asthma, may need treatment from a GP.
How bronchitis affects your airways
The bronchi are the main airways in your lungs, which branch off on either side of your windpipe (trachea). They lead to smaller and smaller airways inside your lungs, known as bronchioles.
The walls of the bronchi produce mucus to trap dust and other particles that could otherwise cause irritation.
Bronchitis occurs when an infection causes the bronchi to become irritated and swollen (inflamed), which causes them to produce more mucus than usual. Your body tries to shift this extra mucus through coughing.
Symptoms of bronchitis
The main symptom of bronchitis is a hacking cough. It is likely that your cough will bring up thick yellow-grey mucus, although this does not always happen.
Your cough may last for several weeks after other symptoms have gone, and you may find the continual coughing motion makes your chest and stomach muscles sore.
Other symptoms of bronchitis may include:
- a tight feeling in your chest
- sore throat
- slight fever and chills
- blocked nose and sinuses
- aches and pains
These symptoms, although unpleasant, are usually not severe and you may not need to see your GP. However, the symptoms of bronchitis can be similar to those of pneumonia (an infection that causes inflammation in your lungs), so it is important to look out for any changes in your symptoms.
When to see your GP
See your GP as soon as possible if any of the following apply:
- your cough is very severe or lasts longer than three weeks
- you have a constant fever for more than three days
- you cough up mucus streaked with blood
- you develop rapid breathing (more than 30 breaths a minute) or chest pains
- you become drowsy or confused
- you have had repeated bouts of bronchitis
- you have an underlying heart or lung condition, such as asthma, emphysema (damage to the small airways in your lungs), congestive heart failure (weakness in the heart that leads to fluid in your lungs) or chronic obstructive pulmonary disease (long-term lung damage).
Causes of bronchitis
Viral or bacterial infection
The bronchitis infection can be caused by either a virus or bacteria, although viral bronchitis is much more common.
In most cases, bronchitis is caused by the same viruses that cause the common cold or influenza (flu). The virus is contained in the millions of tiny droplets that come out of the nose and mouth when someone coughs or sneezes.
These droplets typically spread about 1m (3ft). They hang suspended in the air for a while, then land on surfaces where the virus can survive for up to 24 hours. Anyone who touches these surfaces can spread the virus further by touching something else.
Everyday items at home and in public places, such as door handles and keyboards, may have traces of the virus. People usually become infected by picking up the virus on their hands from contaminated objects and then placing their hands near their mouth or nose. It is also possible to breathe in the virus if it is suspended in airborne droplets.
Breathing in irritant substances
Bronchitis can also be triggered by breathing in irritant substances, such as smog, chemicals in household products or tobacco smoke.
Smoking is the main cause of chronic (long-term) bronchitis, and it can affect people who inhale second-hand smoke as well as smokers themselves.
You may also be at risk of bronchitis if you are often exposed to materials that can damage your lungs, such as grain dust, textiles (fabric fibres), ammonia, strong acids or chlorine. This is sometimes referred to as occupational bronchitis, and usually eases once you are no longer exposed to the irritant substance.
If you have bronchitis, you may not need to see your GP unless your symptoms are severe.
If you do see your GP, they will usually be able to make a diagnosis by asking about your symptoms and listening to your chest using a stethoscope.
Ruling out other conditions
Your GP may need to rule out other lung infections, such as pneumonia, which has symptoms similar to those of bronchitis. If your GP thinks you may have pneumonia, you will probably need a chest X-ray. Your GP may also take a sample of mucus for testing.
If your GP thinks that you may have an undiagnosed underlying condition, such as asthma or emphysema (damage to the small airways in your lungs), they may also suggest a pulmonary function test. Your GP will ask you to take a deep breath and blow into a device called a spirometer, which measures the volume of air in your lungs. A decreased lung capacity can indicate an underlying health problem.
Most cases of bronchitis do not need treatment from a GP and the symptoms can be managed easily at home. There is no cure for chronic bronchitis but healthy living, especially stopping smoking, will help.
Managing symptoms at home
If you have bronchitis:
- Get plenty of rest.
- Drink lots of fluids. This helps prevent dehydration and thins the mucus in your lungs, making it easier to cough up.
- Treat headaches, fever and aches and pains with paracetamol or ibuprofen (ibuprofen is not recommended if you have asthma).
There is little evidence that cough medicines work and the Medicines and Healthcare products Regulatory Agency (MHRA) has recommended that over-the-counter (OTC) cough medicines should not be given to children under the age of six.
As an alternative to an OTC cough medicine, try making your own mixture of honey and lemon, which can help soothe a sore throat and ease your cough.
If you smoke, you should stop immediately. Smoking aggravates bronchitis and increases your risk of developing a chronic (long-term) condition. Stopping smoking while you have bronchitis can also be the perfect opportunity to quit altogether.
Although treatment from a GP is rarely necessary, there may be times when you should see your GP (see Symptoms of bronchitis).
Your GP will not routinely prescribe antibiotic treatment as bronchitis is nearly always caused by a virus. Antibiotics have no effect on viruses, and prescribing them when they are unnecessary can, over time, make bacteria more resistant to antibiotic treatment.
Your GP will only prescribe antibiotics if you have an increased risk of pneumonia. If you are prescribed antibiotics for bronchitis, it is likely to be a five-day course of amoxicillin, oxytetracycline or doxycycline.
Possible side effects of these medicines include nausea, vomiting and diarrhoea, but they are uncommon.
The following advice may help prevent bronchitis.
- Stop smoking. Tobacco smoke can make a current infection worse and makes you much more likely to develop chronic bronchitis.
- Maintain good hygiene. Bronchitis is usually caused by a virus, which spreads through either direct contact or through coughing and sneezing. Washing your hands often and using disposable tissues can help prevent the spread of infection.
- Protect yourself at work. If you work with substances that can irritate your lungs, always wear a mask that covers your nose and mouth.