Hello,
It can be due to parasthesia skin or neurodermatitis. Parasthesia is due to dysfunctioning of neurons. It can be due to diabetes, hypothyroidism, peripheral vascular disease, vitamin B12 deficiency, neujrological causes or malnutrition.
Get your blood sugar and thyroid hormones levels evaluated. You can take some vit B12 for some days and see if the symptoms improve. If the symptoms persist then get the above mentioned possibilities ruled out from a neurologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
what kind of test i need to do?
I think you need lab work and a physical exam.