What are the chances of being diagnosed with als at age 31? have had frequent muscle twitching in legs, now all over, plus hand stiffness and now tight throat/breathing trouble. very scared?

ALS rare in women: Symptoms are certainly similar to ALS. Although extremely rare, has been reported in women. Symptoms alone suggest consultation with neurologist is necessary, firstly because you might have a neurological problem & secondly for your psychologic well-being. Good luck.

Unusual: Would be somewhat reluctant to label you with ALS at this point, but you need an evaluation of breathing and swallowing urgently. A variety of disorders could present in this fashion. If symptoms continue to worsen would seek emergency department visit. A neurologist should be involved. Hope this gets pinned down and your symptoms get controlled.