In a question above, I have spoken about what is asthma please read that section.
However when to comes to treatment the most important thing is to note that the condition is managed and note cured.
Management includes knowing exactly what are the irritants that cause you to have an asthmatic attack. They differ from person to person but often include dust, pollen, hay, smoke, diesel fumes, extreme cold etc.
The second level of management is medical treatment . There are drugs we can prescribe that help to open the airway incase one has trouble breathing. They are called brocho-dilators. The most famous is called Ventolin.
In the event an attack is very severe we can use a machine called a nebulizer and can even give drugs via injections. Such events are very scary and are life threatening. We always hope to avoid such.