Hi
Welcome to the MedHelp forum!
The pain that comes and goes could be due to atherosclerosis of deep vein, some clot or a nerve compression. It can also be a pressure point where the whole body weight gets centered due to incorrect posture or footwear. Arthritis, tendonitis, bursitis could also be the cause. It is difficult to comment beyond this at this stage. Do consult your doctor.
Hope this helps. Take care!