What Causes Twitching Sensation In Bottom Lip And Tingling Sensation Above Buttocks?

For the last 2/3 days i have had a strange twitch/quivering sensation in the left hand side of my bottom lip, i have only noticed it of a night time so far when i am laying in bed. Could you tell me what this could be and whether i need to see my gp? Also last week i had a numb/burning/tingling sensation in the bottom of my back just above my bum,it lasted for 2/3 days and then havent noticed it again, any indication on what this could be?!