Not a few bubbles that disappear fast — this is thick, stubborn foam that sits there like a beer head, and it happens when protein starts slipping through kidney filters that were never supposed to let it escape. TrackSleep
Think of the kidney like a fine mesh coffee filter. When the mesh tears, the grounds do not stay put anymore. They leak through the cracks, and that is exactly what happens when albumin starts showing up in urine.
Then comes swelling. Ankles that puff up by evening, shoes that feel tighter,
