The unfortunate truth about asthma is that we don't know what causes it. Asthma itself is a chronic inflammatory disease of the airways which can affect people in different ways. The one way that everyone experiences it the same, however is that the airways to your lungs meet a trigger and swell up, narrow, and fill with mucus. This can mean spasms, difficulty breathing and other kinds of wheezing and resistance.
What we do know is that there are certain triggers that seem to be fairly consistent for asthma. One is allergens. The majority of people who have asthma also have some allergy to an airborne substance. However, around 20% of people do not, so the two aren't necessarily linked. For others, food will cause an asthmatic reaction, which also sounds a lot like an allergy problem. Smoking and some medications can also cause similar reactions and triggers for asthma.
However, there are non-substance based triggers. For example, exercise can induce an asthma attack, or even simply having heartburn. On top of this, you can find weather and emotions also causing the asthma to hit.
For most sufferers of asthma, it's essential that they keep a record of what has happened when an asthma attack occurs. Because of the enigmatic nature of asthma, it's up to each patient to figure out what his/her triggers are and maintain them on a personal level. 
There are a lot of simple things that are good to know how to do when it comes to basic, everyday medical training. Schools have programs like BAT (Basic Aid Training) for things like this, but chances are you've gotten to do something as simple as: Take a 2-Step Radial Pulse.
Step 1: Find and grab the person's wrist with 3 fingers (your pointer, middle and ring fingers) on the spot below the thumb where the hand and the wrist meet (palm-side). Press down until you feel the pulse.
Step 2: Here's where you measure the strength, the rate and regularity. This is the harder part: Is the pulse easy to notice? Or is it very faint? Does it come in regular intervals or is there noticeable increases and decreases in speed? How many beats in 60 seconds? The normal rates should be between 60 and 100 for adults (ages roughly 11+), 70 to 120 for children ages 1-10, and 70 to 120 for children under 1 year old. In some circumstances, people who are in exceptional physical state will only beat 40 to 60 beats per minute (BPM).
To keep it simple for yourself, remember the adult numbers and work off of those: 60-100, children are a bit higher, fit people are a bit lower. 

I would love for you to get in contact with me today via Facebook, Twitter, Google+, etc. This will allow me to present you with the latest information, new blog posts, etc. that I publish on a fairly regular and routine basis. In addition, it will allow me to stay in contact with you, provide help, answer questions, etc. This is a great win win situation.

So send me that friend request, follow request, etc., and I will be more than glad to accept it and send one right back to you. I thank you in advance for taking the time to reach out and connect. I look forward to socially networking with you.