Chronic respiratory diseases: What triggers an asthma attack?

Asthma is a chronic breathing disorder characterized by recurrent attacks of breathlessness and wheezing. Some causes and triggers are common to all people with asthma, and some are more individual. Although the fundamental causes of asthma are not completely understood, the strongest risk factors for developing asthma are inhaled asthma triggers. These include:

• indoor allergens (for example house dust mites in bedding, carpets and stuffed furniture, pollution and pet dander);
• outdoor allergens (such as pollens and moulds);
• tobacco smoke; and
• chemical irritants in the workplace.

Other triggers can include cold air, extreme emotional arousal such as anger or fear, and physical exercise. In some people, asthma can even be triggered by certain medications, such as aspirin and other non-steroid anti-inflammatory drugs, and beta-blockers (which are used to treat high blood pressure, heart conditions and migraine). Urbanization has also been associated with an increase in asthma, however the exact nature of this relationship is unclear.

According to WHO estimates, 339 million people suffer from asthma globally. Although asthma cannot be cured, appropriate management can control the disorder and enable people to enjoy good quality of life. In addition, some children with milder forms of asthma outgrow their symptoms with age.