Hi, I Have Had What I Think Is Superficial Phlebitis

Hi, I have had what I think is superficial phlebitis on the backs of both of my knees and upper calves. Basically, it looks like bruised red veins. Not blue or purple veins, no bulging or hardness. I wear compression stockings and it seemed to lighten during summer but has come back in winter. I don't have any pain, tenderness, or swelling. Should I be concerned about this? I exercise everyday and I'm a little worried about continuing. I am a healthy weight and have no medical history out of the norm. I'm a 29 year old female, 5'7 and don't smoke or drink. Thanks.