What Causes Leg Discomfort Early In The Morning?

Hi,sir i am 30 years old,sir, from last 1 month my left side leg are not comfortable when get up rise in the morning for standing proper,after 1 hour walking then i feel better,but when sit on the office chair i not sit proper,but if i waking and standig full day then i not feel any pain,i take some medicine acoording to doctor but not feel good, pls give me better sugation....