nephrotic syndrome

A 25-year-old female with no significant past medical history presents with progressive periorbital and lower extremity edema for one week. She denies recent fever, chest pain, shortness of breath, allergies, or recent travel. Vitals include BP 120/90, HR 90, RR 18, Temp 98.7F. Exam shows a developmentally normal female in no acute distress. She has bilateral pitting edema up to knees without skin changes, but the rest of the exam is normal. Her pregnancy test is negative. What is the likely diagnosis?