Is Swollen Vein In Leg With Tightness And Pain A Cause For Concern?

I will try a few days ago when getting out of bed on my right lower leg ehen getting out of bed it felt as tho I puled maybe a tendon ftom the bone on the back sid kinda of like a chatlie horse as few days ptogress it seem to ease up but now a vien on the same leg behind or side is now swollen some and is a bit painful ? A serious problem or ?