Asthma symptoms are caused by inflammation in the tubes that transport air to our lungs, known as the bronchi.

When the body comes into contact with triggers such as allergens, infections and certain environmental stimuli, the airways become irritated and inflamed therefore resulting in restricted airflow.

The constricted airways produce symptoms such as shortness of breath, coughing, wheezing and a tight chest.

What are the causes of asthma?

The direct cause behind asthma is not yet fully understood. There are various theories linking it to both genetics and our environment. Research has shown that you are more likely to develop the condition if:

  • you have a family history of asthma
  • you have been diagnosed with eczema 
  • you were born prematurely and needed the use of a ventilator
  • your mother smoked whilst pregnant
  • you had a low birth-weight
  • or you were exposed to secondhand smoke as a child.

Up to the age of 15 years, young boys are more likely to develop the condition than young girls.

After puberty, it is predominantly adult women who experience the condition as it is often attributed to a change in hormones around the time of menopause.

Asthma tends to occur when someone with a genetic predisposition to the disease comes into contact with an allergic trigger which causes airway stricture.

The World Health Organisation (WHO) estimates that asthma susceptibility is half due to genetics and half due to environmental factors.

Environment and asthma

Where we live and how we live can have an effect on the likelihood of asthma developing.

Asthma is a highly common condition especially within westernised society and is continuing to grow.

A combination of both indoor and outdoor environmental factors can contribute to an allergic asthmatic reaction. These include air pollution, animal dander, dust mites, smoke and mould.

Paying attention to environmental factors is important when looking to improve the health of people with asthma.

Research suggests that asthma is less common in rural areas where children are more likely to come into contact with farm animals and parasites.

These findings support the hygiene hypothesis theory which suggests exposure to a diverse range of microorganisms in childhood has a positive effect on building a child’s immunity to asthma and other allergic diseases.

Genetics and asthma

Our understanding of asthma and our genetic makeup is improving year on year.

There are ongoing genome wide association studies (GWAS) looking into the link between genetics and asthma. The studies are working to identify the specific genes that make a person susceptible to the condition.

Some families can be found to have a strong asthma presence. This is because parents can pass asthma on to their children. As our genes are a highly contributing factor in the development of asthma you may be predisposed at birth to show asthma symptoms.

Up to now approximately 100 genes have been identified as having links to the condition.

The genes can be categorised by: whether they are a susceptible gene; whether they contribute to the severity of the condition; whether they have an effect on treatment response; or whether they alter lung or immune function.

What can worsen asthma symptoms?

It is important to try and keep your asthma as well managed as possible in order to minimise the chances of having an asthma attack and potentially spending time in hospital.

Asthma symptoms are likely to worsen if you fail to take your medication as prescribed. In particular you should be using your preventer medication as your doctor has advised. Regular use helps your body to manage its initial reaction to potentially dangerous allergens.

Not attending your doctor’s practice for regular check ups can be detrimental to your health.

Making an appointment with your doctor or nurse specifically about your asthma condition gives you the opportunity to discuss how asthma is affecting your day-to-day life. It also provides your doctor with the time to review your medication and check that you are receiving the best treatment for your condition.

Those living with asthma may also be encouraged by their doctor to maintain a healthy weight, as being overweight has been linked to an increase in asthma symptoms.

Can you stop yourself from getting asthma?

Unfortunately it is not currently possible to prevent asthma from developing.

If you are predisposed due to your genetic make up and you come into contact with a substance which causes a hyperresponsive reaction, then it is highly likely that you will be diagnosed with asthma.

Over the years your asthma may improve or worsen at different times due to a number of reasons.

You can increase your chances of living symptom free for longer if you take care of yourself. This includes taking responsibility for your own health by staying fit, preventing illness where possible, taking your medication as outlined by your doctor, getting help to quit smoking if needed, attending your GP practice for regular reviews and accepting the flu-jab when offered.

Through a combination of asthma medications and environmental awareness those with asthma can manage their condition to a safe level.

Page last reviewed:  18/07/2018