Asthma attacks occur when the bronchi and bronchioles become inflamed, this reduces the space throughout which air
travels through the lungs. This causes the asthmatic victim to work harder to move air in and out of their
Asthma attacks usually begin with a dry cough and mild chest heaviness. As an attack grows, wheezing develops
and increases in pitch; breathing becomes more difficult and coughing produces thick, stringy mucus.
As the airway irritation prevents some of the oxygen-rich air from reaching the alveoli in the lungs, the cells
of the body start burning oxygen at a higher rate, which increases the body’s demand for oxygen.
The frequency of asthma attacks varies considerably among asthma suffers. Some people have daily attacks, while
others can go months or even years without having an attack.
Narrowing of Airways in Asthma
People with asthma have extra responsive or hyper responsive
airways. Their airways react by contracting or obstructing when they become irritated. This makes it difficult for
them to move air in and out of their lungs.
This narrowing or obstruction is caused by:
* Airway inflammation (the airways in the lungs become red, swollen and narrow)
* Broncho-constriction (the muscles encircling the airways tighten or go into spasm)
If a normal airway has been exposed to certain stimulus (i.e. inhaled
allergen like grass pollen), it becomes inflamed, swollen and plugged with mucus. This makes the airway opening
smaller and more difficult for air to get through. It's easy to see why children, who have small airways to begin
with, would have difficulty breathing if this happens.
If the opening of a typical airway is exposed to certain stimuli (such as cold air or enthusiastic exercise), the
muscle fibres surrounding the airway contract thus making the airway opening even smaller. This makes breathing for
the sufferer much more difficult.
Causes Of Asthma
Asthma attacks are caused by airway hyper receptiveness. The most common causes of an asthma attack are very small
lightweight particles transported through the air and inhaled into the lungs.
When they enter the airways, these particles which are known as environmental triggers, cause an inflammatory
reaction in the airway walls which results in asthma attack.
For some people environmental triggers are allergens. These are natural substances, such as plant pollen and mould
spores, animal dander (tiny pieces of animal hair and skin), and faecal material from dust mites and
Allergens produce an inflated response of the immune system in which a specific antibody immunoglobulin E,
initiates an inflammatory response. These same allergens usually cause little or no response in non-allergic
The allergens involved in asthma are similar to those in rhinitis. The particle size of pollens (>20 microns)
mean they are more likely to cause conjunctivitis, rhinitis and pharyngitis as well as asthma. Allergens from
faecal particles of the house-dust mite are the most important extrinsic cause of asthma world-wide.
Chemical irritants trigger an inflammatory response differently to allergen-triggered asthma.
Some people are sensitive to common chemical irritants, such as perfume, hairspray, make-up, and household
Other chemical irritants include industrial chemicals and plastics, as well as many forms of air pollution, such
as exposure to high levels of ozone, car exhaust, wood smoke, and sulphur dioxide.
Aggravation from within the body is known as physiological triggers and includes exercise and infections, such as
the common cold. Sometimes eating certain types of food can cause an asthma attack.
Chemicals found in food or drugs such as aspirin and ibuprofen can be especially problematic for many asthma
sufferers. Emotions, such as expressions of grief, shouting, or laughing, can also provoke rapid inhalation of
oxygen causing the airways to narrow which trigger an attack. Many asthmatics are especially responsive to physical
exercise in cold weather.