Introduction

Bronchitis is an infection of the main airways of the lungs (bronchi), causing them to become irritated and inflamed.

The main symptom is a cough, which may bring up yellow-grey mucus (phlegm). Bronchitis may also cause a sore throat and wheezing.

Read more about the symptoms of bronchitis.

When to see your GP

Most cases of bronchitis can be treated easily at home with rest, non-steroidal anti-inflammatory drugs (NSAIDs) and plenty of fluids.

You only need to see your GP if your symptoms are severe or unusual – for example, if:

  • your cough is severe or lasts longer than three weeks
  • you have a constant fever (a temperature of 38°C – 100.4°F – or above) for more than three days
  • you cough up mucus streaked with blood
  • you have an underlying heart or lung condition, such as asthma or heart failure

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, and a sample of mucus may be taken for testing.

If your GP thinks you might have an undiagnosed underlying condition, they may also suggest a pulmonary function test. You will be asked to take a deep breath and blow into a device called a spirometer, which measures the volume of air in your lungs. Decreased lung capacity can indicate an underlying health problem.

Treating bronchitis

In most cases, bronchitis will clear up by itself within a few weeks without the need for treatment. This type of bronchitis is known as "acute bronchitis". While you are waiting for it to pass, you should drink lots of fluid and get plenty of rest.

In some cases, the symptoms of bronchitis can last much longer. If symptoms last for at least three months, it is known as "chronic bronchitis". There is no cure for chronic bronchitis, but there are several medications to help relieve symptoms. It is also important to avoid smoking and smoky environments, as this can make your symptoms worse.

Read more about treating bronchitis.

Why do I have bronchitis?

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.

Most cases of acute bronchitis develop when an infection causes the bronchi to become irritated and inflamed, which causes them to produce more mucus than usual. Your body tries to shift this extra mucus through coughing.

Smoking is the most common cause of chronic bronchitis. Over time, tobacco smoke can cause permanent damage to the bronchi, causing them to become inflamed.

Read more about the causes of bronchitis.

Complications

Pneumonia is the most common complication of bronchitis. It happens when the infection spreads further into the lungs, causing air sacs inside the lungs to fill up with fluid. 1 in 20 cases of bronchitis leads to pneumonia.

People at an increased risk of developing pneumonia include:

  • elderly people
  • people who smoke
  • people with other health conditions, such as heart, liver or kidney disease
  • people with a weakened immune system

Mild pneumonia can usually be treated with antibiotics at home. More severe cases may require admission to hospital.

Read more about the treatment of pneumonia.

Who is affected

Acute bronchitis is one of the most common types of lung infection, and is one of the top five reasons for GP visits.

Acute bronchitis can affect people of all ages, but is most common in younger children under the age of five. It is more common in winter, and often develops following a cold, sore throat or flu.

It is estimated that there are around 2 million people in the UK affected by chronic bronchitis. Most of these are adults over the age of 50.

Symptoms

The main symptom of bronchitis is a hacking cough. It is likely that your cough will bring up thick yellow-grey mucus (phlegm), although this does not always happen.

Other symptoms of bronchitis are similar to those of other infections, such as the common cold or sinusitis, and may include:

  • sore throat
  • headache
  • runny or blocked nose
  • aches and pains
  • tiredness

If you have bronchitis, your cough may last for several weeks after other symptoms have gone. You may also find that the continual coughing makes your chest and stomach muscles sore.

Some people may experience shortness of breath or wheezing, due to inflamed airways. However, this is more common with long-term (chronic) bronchitis.

Long-term (chronic) bronchitis

Chronic bronchitis is often known as chronic obstructive pulmonary disease (COPD).

The symptoms of COPD can include:

  • wheezing
  • increasing breathlessness when exercising or moving around
  • a persistent cough that brings up mucus (phlegm)
  • frequent chest infections

The symptoms are often worse in the winter, and it is common to have two or more flare-ups a year. A flare-up is when your symptoms are particularly bad.

When to see your GP

See your GP as soon as possible if:

  • your cough is very severe or lasts longer than three weeks
  • you have a constant fever (a temperature of 38°C – 100.4°F – or above) for more than three days – this may be a sign of flu or a more serious condition, such as pneumonia
  • 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 should also contact your GP if you have an underlying heart or lung condition, such as:

  • asthma
  • heart failure – weakness in the heart that leads to fluid in your lungs
  • emphysema – damage to the small airways in your lungs

Causes

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 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 on them. People usually become infected by picking up the virus on their hands from contaminated objects, and then placing their hands near their nose or mouth. 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 long-term (chronic) bronchitis, and it can affect people who inhale second-hand smoke, as well as smokers themselves.

Read information about treatments to quit smoking.

Occupational exposure

You may also be at risk of bronchitis and other forms of chronic obstructive pulmonary disease (COPD) if you are often exposed to materials that can damage your lungs, such as:

  • grain dust
  • textiles (fabric fibres)
  • ammonia
  • strong acids
  • chlorine

This is sometimes referred to as "occupational bronchitis", and usually eases once you are no longer exposed to the irritant substance.

Read more information about the causes of COPD.

You can also read the Health and Safety Executive's 2013 report on COPD in Great Britain attributed to occupational exposure (PDF, 58kb).

Treatment

Most cases of bronchitis do not require treatment from a GP, and the symptoms can be easily managed at home.

There is no cure for chronic bronchitis, but healthy living will help. In particular, you should stop smoking, if you smoke.

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 – although ibuprofen is not recommended if you have asthma 

There is little evidence that cough medicines work – read more about treating coughs. The Medicines and Healthcare Products Regulatory Agency (MHRA) has recommended that over-the-counter cough medicines should not be given to children under the age of six.

As an alternative to an over-the-counter cough medicine, try making your own mixture of honey and lemon, which can help soothe a sore throat and ease your cough.

Stop smoking

If you smoke, you should stop immediately. Smoking aggravates bronchitis and increases your risk of developing a long-term (chronic) condition.

Stopping smoking while you have bronchitis can also be the perfect opportunity to quit altogether.

Antibiotics

Although treatment from a GP is rarely necessary, there may be times when you should see one – read more about when to see your GP.

Your GP will not routinely prescribe antibiotics, 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 developing complications, such as pneumonia. Antibiotics may be recommended for:

  • premature babies
  • elderly people over the age of 80
  • people with a history of heart, lung, kidney or liver disease
  • people with a weakened immune system, which could be the result of an underlying condition or a side effect of a treatment such as steroid medication
  • people with cystic fibrosis

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.

Chronic bronchitis

Chronic bronchitis is treated in the same way as chronic obstructive pulmonary disease (COPD).

For example:

  • a type of medication called mucolytics can be used to make mucus easier to cough up
  • an exercise programme known as pulmonary rehabilitation can help you cope better with your symptoms

Stopping smoking is also very important if you have been diagnosed with chronic bronchitis or COPD.

Read more about the treatment of COPD.