Asthma vs Bronchitis: What’s the Difference?

Similar symptoms, different causes

Published: Thursday 12 November 2020


comparing asthma and bronchitis

In a lot of ways, asthma and bronchitis are very similar conditions. They’re both respiratory illnesses. They both cause symptoms such as coughing, chest tightness and shortness of breath. In some instances, they’re treated with the same medicines as well. Sometimes, the two present in such similar ways that people confuse one for the other.

But despite their commonalities, it’s still important to be able to distinguish between the two. While some forms of bronchitis are treated similarly to asthma, others are in fact very different. Asthma symptoms often come and go, while bronchitis may be short-term or chronic. Bronchitis is in some instances contagious, whereas asthma is not. Knowing how the two differ can make accessing the right treatment substantially easier - and get you on the road to recovery sooner.

Symptoms, similarities and differences

As respiratory conditions, bronchitis and asthma affect the body in very similar ways. Both cause the airways to become inflamed and swollen, which makes it more difficult for air to reach the lungs. This leads to the classic symptoms associated with both, which include:

  • Wheezing
  • Shortness of breath
  • Chest tightness
  • Coughing

While both conditions typically cause coughing, people with bronchitis will produce mucus when they cough. Asthma, on the other hand, usually causes dry coughing instead.

Bronchitis also differs from asthma in that it comes in two forms: chronic and acute. While chronic bronchitis tends to be quite like asthma, acute bronchitis is usually caused by a virus or bacteria and thus causes a number of extra symptoms. These include:

  • Fever
  • Chills
  • Body aches
  • General malaise

As an infection, acute bronchitis also differs from chronic bronchitis and asthma in that it’s contagious. The good news, however, is that it’s also temporary. In most instances, the symptoms will only last between a few days and a few weeks while the symptoms clear up.

Bronchitis - the causes

While bronchitis and asthma have similar symptoms, their causes are actually very different. As mentioned above, acute bronchitis is usually caused by a virus or bacteria. Chronic bronchitis, on the other hand, is more likely to be caused by a combination of environmental factors, lifestyle factors and pre-existing medical conditions. These include:

  • Smoking or exposure to tobacco smoke
  • Exposure to chemical fumes and dust
  • A weakened immune system
  • Being above 40 years of age

People with chronic bronchitis will find that their condition flares up due to environmental factors that irritate their airways.

Asthma - possible causes and risk factors

Like chronic bronchitis, asthma is often triggered due to environmental factors - but it isn’t necessarily caused by them. We still don’t know exactly what causes people to develop asthma, but evidence suggests there are a number of risk factors to watch out for.

The first risk factor is genetics. Research suggests that asthma and allergies tend to run in families, meaning people with asthma may be genetically predisposed to having airways that are more prone to inflammation and sensitive to irritants. If a child’s parents have asthma, it’s much more likely they will develop asthma themselves.

There are a number of factors in infancy and early childhood that increase the risk of asthma, as well. Research shows that smoking during pregnancy greatly increases the likelihood that the child will develop asthma or other breathing problems after birth. Babies who are born prematurely are also more likely to develop asthma - especially if they need a ventilator to help them breathe after birth. Babies and children under the age of two who develop bronchiolitis, a viral condition that inflames the airways, are also more likely to get asthma later in life.

Asthma doesn’t just emerge in childhood, however - adults can develop the condition as well. Adult-onset asthma is more likely to be caused by environmental factors than asthma in children, and these are often the same as those that trigger chronic bronchitis. Asthma caused by chemicals and workplace irritants is known as ‘occupational asthma’, and is a common cause of asthma in adults.

Asthma triggers

While asthma sometimes shares triggers with chronic bronchitis, it has a number of other common triggers not typically associated with bronchitis. In addition to occupational asthma, some people may experience allergy-induced asthma, which includes triggers such as:

  • Pollen
  • Mold spores
  • Cockroach waste
  • Skin particles
  • Pet dander
  • Pollen

Alongside occupational and allergy-induced asthma, it’s also common for asthma sufferers to experience flare-ups and asthma attacks during exercise. Exercise-induced asthma can be made worse under cold and dry weather conditions.

Asthma and bronchitis together

Bronchitis and asthma are similar conditions, but they aren’t mutually exclusive. Unfortunately, people with asthma can also get acute bronchitis if they catch an infection or virus. This is often referred to as ‘asthmatic bronchitis’.

When a non-asthma sufferer catches a respiratory infection, the body produces mucus in an attempt to clear it. Asthma sufferers, however, already have a higher amount of mucus in the airways. This means that acute bronchitis can cause even more mucus to collect in the airways - making it much harder to breathe.

People with asthma will be able to tell if they have acute bronchitis as well from the symptoms mentioned earlier, such as fever, chills and body aches. If your asthma symptoms have become worse and you have symptoms of acute bronchitis, you should inform your GP so they can advise on how to manage it while the infection clears.

How to tell which condition you have

It’s usually quite easy to tell if you have acute bronchitis. The symptoms not usually associated with asthma and chronic bronchitis, such as fever and chills, are a good indicator that your bronchitis is short-term and will get better within a few weeks.

Unfortunately, it isn’t always easy to tell whether you have chronic bronchitis or asthma. The best way to find out which condition you have is to consult your GP. They’ll ask you a series of questions about your symptoms, including how severe they are, when they started, and if they get worse when exposed to certain triggers. They’ll also use a stethoscope to listen to your lungs and order further tests in order to come to a diagnosis.

How each condition is treated

The appropriate treatment depends on the condition you have. In most cases, acute bronchitis isn’t treated with antibiotics because it’s often caused by a virus, rather than bacteria. For that reason, doctors usually recommend plenty of rest, fluids and painkillers until the symptoms clear.

Chronic bronchitis and asthma, however, share similar treatments and medicines. Both are often treated with bronchodilators - inhalers designed to open the airways, clear mucus and help you breathe easier. They come in two forms:

  • Short-acting bronchodilators, which take effect within minutes and are designed to relieve flare--ups
  • Long-acting bronchodilators which take longer to take effect but last all day

Short-acting bronchodilators are taken as-needed, whereas long-acting ones are taken at the start of every day in order to keep symptoms under control. If your symptoms are severe, you may also be prescribed a steroid inhaler, which reduces inflammation and swelling in the airways.

The bottom line

Any condition that affects the respiratory system can be extremely frightening. If you start to experience any of the symptoms associated with asthma or bronchitis, knowing what to look out for and what to tell your doctor can help you find the right treatment and improve your symptoms sooner.

The good news is that these conditions are usually very manageable with the right treatment. Acute bronchitis usually goes away on its own, and asthma and chronic bronchitis can be controlled with the right treatments and steps to prevent flare-ups.

Harry Walker

Authored by Harry Walker

Patient Care Specialist


After graduating with a degree in Journalism at City, University of London, Harry joined the Pharmica team as a Patient Care Specialist and content writer.

In addition to helping in the dispensary, Harry consults with our in-house pharmacists to produce engaging, informative and expert content for our patients.

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