I m 19, I haven t been very active in the past few months. In June, I tried doing some intense leg stretch, and I started feeling pressure in this one spot on left side of my left calf. It went away after a week, and came back three weeks later, this time in the same spot as well as in two other spots above by my knee and below by my ankle. It s been two weeks now and the sensation hasn t subsided; now it feels like a deep itch inside my muscle from the area behind my left knee to the muscle by my ankle. It is really worrying me.