WARNING!
Unlike other diseases, which harm your kidneys because of too much inflammation, COVID-19 directly attacks and kills your kidney cells that filter your blood through the ACE2 receptor.
Personally, my kidneys were swollen after I got a fever from COVID. They did not hurt, but I couldn't sleep on my back without them bothering me. By about the 5th day the swelling went away. My kidneys felt like a deflated balloon but nothing painful and any other problems with urination other than a lot of foam on my first piss. Later, after having no other symptoms for a while, I still noticed fluid in my lungs every morning, so I looked for long hauler treatments. I purchased and took Lugol's iodine as recommended. The next day my kidneys have been bothering me since with always some foam/bubbles in my urine. It's been a week and I'm still having problems but they come and go now. Possible permanent kidney damage isn't worth it. Look for other remedies if you're a long hauler.
