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Causes of Asthma

Asthma does not have a single known cause but there are several factors that may contribute to the development of this condition. These include atopy, genetic predisposition (having something in your genes that makes you likely to develop asthmas), diet and the environment.

Atopy is a general genetic condition that makes people more likely to develop allergic reactions to various substances (called allergens). It increases the likelihood of a person having asthma, eczema or hay fever. All three are related to genes that a person will have inherited from their parents – so there is often a family history of these conditions.

Exposure to industrial or atmospheric pollution may also cause asthma symptoms. More than 200 industrial substances are known to bring on asthma.

People with atopy are more likely to develop asthma in response to industrial and other pollutants than are people who do not have atopy, and to do so more quickly.

When a person has asthma, an attack can be started by a number of different things. These include:

  • Breathing in (inhaling) certain allergens, such as pollens or fungal spores, animal allergens or house dust mites
  • Viral and bacterial chest infections
  • Seasonal changes
  • Exercise, especially when it is cold
  • Some medicines, especially beta-blockers and aspirin
  • Strong smells and perfumes
  • Smoke, pollution or vehicle exhaust fumes
  • Worry and stress
  • Alcohol
  • Foods such as nuts and shellfish, or food additives such as tartrazine.

In a small number of people with asthma, an attack can be triggered by aspirin or other NSAIDS (non-steroidal anti-inflammatory drugs) such as ibuprofen. Paracetamol is generally a safer painkiller for those with asthma.

It is also recognised that beta-blocker drugs (which are used to in the treatment of heart disease and high blood pressure), like atenolol and propranolol, trigger asthma attacks.

A recent study has found that fumes given off by cleaning products and solvents in the home including floor cleaners, room fresheners and polish may cause asthma in young children (2).