Hi, this could be due to neuropathy, low calcium levels, vitamin B deficiency etc. Other possibility is TIA (transient ischemic attack). How old are you? Any history of hypertension or diabetes?
Please get calcium levels done along with thyroid status. Try vitamin B supplements too.
My grandmother has diabetes and my mother has thyroid problems. It started in leg than up to arm only the upper left arm area. My right side feels fine. But I get very shaky and it does not feel right. Like I'm on a drug (do not use drugs