About Asthma

Asthma results when the airways in the lungs become hyperactive and hyper-responsive to irritants. Hyperactive means the lungs are more sensitive to irritants than most peoples’ and hyperresponsive means the airways overreact to things that would be minor irritants in people without asthma. Some have described the asthmatics as having twitchy airways.
When asthmatics are exposed to one or more triggers, it initiates the asthmatic process. The airway that contains cells (inflammatory cells) flare up a process called inflammation. These cells release chemicals. Some of these chemicals tell the body to send more inflammatory cells to the area. The lining of the broncxhial tubes of asthmatics contain more of these special cells . These special cells also release more chemicals into the airway causing all the changes in the lungs and lead to three main processes:

1. Bronchial Muscle Spasm
The bronchial muscle contracts causing the airway to narrow in a process called bronchospasm. These tightened muscles block the airways thus restricting the movement of air.

2. Excess Mucus
Inflammation causes the mucus glands to produce mucus in excess. This mucus clumps together in the airway. Mucus buildup causes swelling of the inner lining of the lungs (mucosal oedema). This results in further narrowing of the bronchial tubes and partial blockage of the airway, hindering breathing. Excess mucus can form plugs that clog very small airways.

3. Coughing and Phlegm Production:
The mucus gland produces sticky sputum (phlegm). When secretions become thick, the individual coughs to remove the unwanted substance. Dry cough is the product of extra thick mucus plugs or bronchioles so blocked that the mucus cannot be removed.

Asthma symptoms can get worse for no apparent reason. However, most asthma symptoms are caused by irritants called triggers. There are various kinds of triggers, some acting in isolation, others working together. The severity of Asthma depends on how many substances in the environment act as triggers and how sensitive the lung is to these substances.

Allergens
An Australian paediatrician, Clemns von Perquet (1974-1929) first coined the term allergy in 1906. He used the term to refer to an foreign substance that provokes the immune system or hypersensitivity. Research has shown that the body’s tendency to produce abnormal immunoglobin E (1gE) in response to foreign substances (allergens) is the strongest identifiable factor for asthma.. A person is said to have atopy (or to be atopic) when he or she is prone to allergy. Allergy tends to occur in families. People are not born with allergies. However, they inherit the tendency to develop some form of allergy. In other words, both the child and the parent might be allergic to something, but not necessarily the same thing. They pass this tendency from one generation to another. Children are more susceptible to allergy induced asthma. These children also show reactions to other allergic conditions such as eczema (dry scaly skin patches), rhinitis (inflammation of the mucus membrane that lines the nose, pharyngitis (sore throat) and conjunctivitis (red eye).

For those with an inherited tendency towards allergies, the more you encounter a particular allergen, the more likelihood that you will develop an allergy from it. The length of these contacts contributes to your becoming allergic. In other words, what you breathe, eat or touch can trigger asthma. Most allergens are so tiny and light that they can circulate in the air for a long time. As children grow up, the percentage of people with atopic or allergic asthma declines.
Although atopic asthma usually manifests before age 35, half adults with asthma are allergic. For some people, allergy builds up over the years until they become strong enough to exhibit symptoms of asthma. Sometimes a change in routine, job or movement to a new environment can expose you to different allergens that can result in asthma.

Common allergens include saliva, fur and dander (tiny flakes of skin) from pets like dogs and cats, moulds and pollens, cockroaches, food and food additives and house dust mites to mention a few. This write-up will not complete without mentioning house dust allergy which is common cause of asthma. Dust mites are extremely little animals that live in dust, feeding on bits of shed human skin and other appetizing little morsels. Dust mites grow especially well in mattresses, pillows and beddings. Evidence points to dust mites as being the most common indoor allergen and major cause of asthma.

Irritants
Some lungs react to certain substances in the air, which are strong enough to trigger asthma. Yet allergic tests reveal no specific allergens. These symptoms develop slowly over several years, may first be noticed at work or when one moves to a new house. Irritants include tobacco smoke, perfumes, pungent odours, combustible substances, formaldehyde or household chemicals and work related triggers (occupational asthma).
Other triggers of asthma include medications (e.g.Aspirin), emotions (anger, anxiety and sadness) and common cold. About 90% of asthma in children are triggered by colds and the ‘flu’. Exercise is another trigger for asthma. Over 70% to 80% of asthmatics have asthma triggered by running especially in cold weather. However, asthmatics should not avoid sports. Exercise induced asthma can be well controlled with drugs.