symptoms please please help
i'm a 21 year old college student, good health. i'm also premed. heres the deal... in january my left eyelid started twitching, not constantly, but several times a day, it lasted about 2 weeks then went away and i felt normal. then in march, it came back, although much much less than before. this time i also noticed that when i raise my arms above my head, and then lower them, i can feel the muscles in my shoulders shake a little (only when i lower them)....it is not something that is noticeable at all to others and not severe at all, i can also feel it in my back when i bend over (but not when i stand back up). It then went away for a good 2 months, and just last week came back. None of this is very severe, but i worry all the time about it, and id say im an anxious person in general. i think because of the premed classes, my head is filled with all these awful scenarios of ALS, brain tumors, etc. and then i go to the internet and research, and its seems like whenever i see the symptoms of a disease, i feel like thats what i have. any ideas?
also, can anybody explain what exactly "weakness" feels like? besides what i described above, i dont feel weak at all, if that makes any sense at all.
confused and worried