Does protein in urine mean kidney damage? Are bubbles in urine normal?

⏰ Timestamps ⏰
0:00 Introduction
1:10 What is proteinuria and what causes it?
16:37 What do bubbles in the urine mean?
18:12 How do we measure proteinuria? What are the pros and cons of different tests (urinalysis, protein/creatinine, albumin/creatinine)?
28:59 How does the amount of protein in the urine relate to prognosis?