According to doctors and scientists from Columbia University, the virus damages the inside of the blood vessels, which causes blood clotting. The blood clots travel through the body and can damage the heart, kidneys and other systems. The virus can also damage organs by itself. In New York City hospitals, 50% of COVID-19 patients had kidney failure in some way. The scientists said that the kidneys have many ACE2 receptors, the same receptor that SARS-CoV-2 uses to sneak into cells.