What is Asthma?
Asthma is a common condition of the lung airways in the respiratory tract. Its cause is not completely clear, though it is known that there are many contributory factors, but it is also known that the number of people affected by the condition is rising.
The reason for an asthma attack is the narrowing of the airways carrying air to and from the air sacs in the lungs. These airways are called bronchioles.
Of the symptoms of cough, wheeze, chest tightness and breathlessness, not everyone will have all these symptoms, and the only symptoms which may be noticeable in children, for instance, with asthma, could be a night cough, or a cough on exercise.
It may be useful to classify asthma into two types, extrinsic and intrinsic.
Extrinsic Asthma (atopic/allergic)
Most frequently occurs in children and refers to a definite external cause of the asthma, occurring in atopic (or allergic) people.
However, a small proportion of this group are adults with late onset asthma, usually attributed to sensitivity developed to materials in the work place.
Intrinsic Asthma (non allergic)
This is late onset asthma, occurring in middle age, where no cause is identified. However, such people may have had childhood asthma.
The usefulness of this way of thinking is that, if the asthma is believed to be extrinsic, any external causes should be considered.