Hi,
Welcome to health care magic,
If this numbness tingling sensations is not troubling your day to day life or it occurs occasionallythen there no need to worry much, because in many cases no apparent cause is found to explain such tingling.
However sometimes this tingling sensations are actually
paresthesia, which are associated with few medical conditions such as:
1) remaining in posture for a long time
2) lack of blood supply to the particular area
3) Diabetes, thyroid state or
vitamin deficiency.
4) Spina
nerve root compression like
cervical radiculopathy or multiple
sclerosis - but these rare possibilities
So if this feeling is constant and troublesome then you need to see physician who will examine you thoroughly with complete medical history and order relevant investigations to rule out above causes.
Do not be worried like I said in most cases the causes are benign and don't need treatment.
Hope this will help you how to proceed further.
Regards,