Asthma is characterised by an extended expiratory [exhalation] and reduced inspiratory [inhalation] breathing phase. This is due to bronchial spasm - a condition caused by a combination of factors. The causes include allergy to a certain substance [allergen], perhaps certain foods, such as eggs, prawns and shell fish; pollutants, physical exertion, viral infection, cold air, tobacco smoke, animal feathers and dander, and even certain conventional medicines. Other factors include chemicals and toxins as well as temperature changes and humidity.
The disorder could also be activated by irritation or infection of the respiratory tract or a gastrointestinal upset, which is typically a result of late or irregular meals, hyperacidity, faulty eating habits, dietetic indiscretion or junk food.
Certain emotional factors such as anxiety and emotional worries may trigger sudden bouts of asthma. Clinicians suggest that a constitutional predisposition could also trigger the disorder - this is supposedly related to desperate feelings of dependence. A childs asthmatic attacks, for example, could be a call for help, or a subconscious appeal to his/her mother for attention.
Research confirms the occurrence of wheezing in certain individuals following a short period of exercise. It is also obvious that respiratory viruses can provoke bronchospasm [airway obstruction] in asthmatics. Age, likewise, is a significant influencing aspect - the first asthma attack reportedly develops before the age of 20.
Some medical researchers also feel that asthma is not entirely hereditary or familial; it is primarily swayed by weather and location changes.