Suggest Treatment For Numbness And Itchiness In The Knee

Ever since last night at around 2200 my left foot has felt numb as if it were asleep. From my knee down it also feels numb with a achy feel to it and it feels stiff. Not sure if this is related, but for 4 days straight now I have had a major pain on the back of my head, only on the left side as well. The pain comes and goes but when it hits it feels like a throbbing feeling. I have tried asprin and to get up and walk around but nothing seems to work.