Asthma is a respiratory disease that can be chronic or episodic. Occurs when the channels through which circulates the air we breathe swell and contract.
Although the classes of asthma are numerous, are divided into two groups: those caused by external agents and has the intrinsic origin.
Extrinsic asthma is caused by agents that cause allergic reactions in the patient. In this group include asthma attacks triggered by pollen, dust, environmental changes, odors, etc..
An over-reaction to fungi and bacteria are the main causes of intrinsic asthma, manifested especially in adults.
The most frequent is that asthma has its origins in a combination of extrinsic and intrinsic causes.
