My lower left leg is swollen, (2-3cms bigger than right) no pain. tingly at times. no dvt (test came back negative) & no injury.(top of knee to ankle)?

Many possible causes: Some causes of leg swelling can include cellulitis, lymphatic obstruction, blood clots, varicose veins and trauma. Have it evaluated by a professional and get the appropriate treatment.

Could be reflux: You may have problems with venous insufficiency. These is what leads to varicose veins and many times presents as swelling without seeing veins on the surface. Ask you r doctor to order a venous reflux study from the vascular lab.