its always my left arm!!!!!

i keep getting weird stuff happening to my left arm. first it was mums thumb and now my elbow is like doing a weird thing idk. it starts doing that when i do the dishes or hold it in like that way in which you hold your papers down when you're writing. idk i asked mum and she said it might be something with my ulna nerve or however its spelt becuz she sez she's had frends who've had that happen 2 them be4

😭but why my left arm 😢