1. What exactly happens inside me to trigger my asthma?
The bronchi (or small tubes that transport air to and from lungs) over-react to some stimuli and set-off a chain of events. Theses stimuli in a non-asthmatic person are encountered by the immune system and ignored but in the case of an asthma patient, the trigger irritates the bronchi walls where the tissues and muscles start to spasm as a response. Soon afterwards, the cells and tissues begin to swell/inflame leading to narrowing of the air tubes allowing lesser oxygen to reach the lungs. This gives a feeling of chest-tightness in many patients. The cells in the bronchi wall then start to produce excessive mucous (also known as phlegm) as a hyper immune response to encountering the trigger which causes further narrowing and obstruction in the bronchi. The production of phlegm in a restricted air passage causes coughing and further breathlessness.
2. What are the triggers I should be wary of?
There are as many causes to asthma as there are symptoms – ranging from genetic to external triggers (stimuli). Here’s a list of the factors found present in most of the cases:
• Heredity: Researches have shown 25 genes associated with asthma common across various races in the world. These genes are all immune-response genes. However, it has also been found that certain genes only cause asthma when combined with certain environmental factors. (Source: Martinez FD (2007). "CD14, endotoxin, and asthma risk: actions and interactions". Proc Am Thorac Soc 4 (3): 221–5. doi:10.1513/pats.200702-035AW. PMID 17607003.)
• Hyper-immune-response to allergens: As discussed in the workings of asthma.
• External Triggers: Pollens, cigarette smoke, outdoor smoke (containing nitrogen dioxide or sulphur dioxide), cold air, cockroach killing sprays, high levels of humidity, high levels of ozone in air, smog, swimming pool chlorine, bleaches, other ammonia or chlorine products that give out fumes, etc.
• Indoor Triggers: Mold spores, carpets, stuffed furniture, pet fur, dust mites, cockroach allergens, aerosols, flour, certain perfumes and chemicals such as detergents.