<s>[INST] Hello, Since a couple of days I have a bulging vein on the top of my right foot and it feels like I have injured myself there and have a trauma, but I don t in reality. It has also happened before and then went away. What could this be and can I do something to stop the discomfort? Thank you [/INST] Hello, Thank you for using Chat Doctor. I read your question and understood your concern. I think you may have a synovial cyst on the top of your foot. This may be an articular cyst or tendon cyst filled with gelatinous fluid. This is not a vein problem. This kind of cyst go way itself and may become later itself. Cause might be from overuse, walking or running too much or overweight. You can do an Ultrasound examination to confirm it. If it bothers you too much you can think about surgery. </s>