What Causes Numbness In Left Arm And Fingers?

dear sir, i am 37 yrs old male, 5 days back when morning wake up , i felt my left arm palm and wrist area affected by numbness .....mainly my middle finger , ring finger and thumb not functioning ..and felt my left arm had very weak ,couldn't hold even pen and tissue paper .after i checked with doctor , and now i am taking medicine, now i feel little improvement.but still not so strong in my arm and not like my right hand. some times when i am sitting above 10 minutes, my left side leg also very fast get numbness.please can u give me the details this is the sign of stroke and heart attack? suppose need treatment how long need to take treatment.? thanks.