Swollen legs and ankles

I am having my second bout of edema in my legs and ankles and feet. The doctor has had me on a diuretic for one week at a time. Tests she ran were negative for obvious causes. Except for a few white blood cells in the urine. She now wants me to see a vascular doctor. I am only finding vascular surgeons. That's scary since I don't want any surgery.

I don't think I eat that much salt. I have been drinking cranberry juice. It's been rather hot and humid here.

Does anyone have any suggestions about this.