Why are the tips of my fingers tingling?

Ever since I let go of the top pole in the metro (to hold my balance), my hand went numb and my fingers started to tingle. You know the tingling feeling you get after your foot or leg regain feeling after numbness? I don't know what it is or why it is happening. Can anybody explain. My dad said it might be carpal tunnel. Mom says it might be that there is no circulation. I don't believe so because I don't go on the computer that much, plus, I think my hand has gotten plenty of circulation during the days that have gone by after this incident.