Do blood tests rule out ASL?

[JMDes]

I went to the hospital yesterday because my legs where really bothering me and they did a bunch of blood/urine tests and I was wondering if that rules out ASL because everything came back normal. I'm having a feeling of not getting enough air when I breath sometimes and my legs and arms are pretty weak most of the time. It is my understanding that ALS usually only afflics one limb at a time. Could this just be a virus or anxiety and I'm only 18 years old.

[JMDes]

Sorry, I put ALS as ASL.

[Al]

I'm no doctor but I'd bet on bacterial or viral. Blood tests don't rule out ALS but can rule out a bunch of other things that cause feelings of weakness like anemia or mono or a pile of other things. Don't start writing out your will yet.
AL.