Proteins are essential in our bodies. Normally, proteins move around in our blood, carrying food, hormones and medicine to all parts of the body. They also help keep water inside tiny blood vessels.
Proteinuria is the name of a medical condition.
It means protein is in the urine. As blood moves through the kidneys, the kidneys filter out waste products, excess fluid and salts. The clean blood cycles back through the body. Most proteins are too big to go through the kidneys, so usually no protein is found in urine. Sometimes infection or toxic chemicals damage the kidneys, and this makes protein show up in the urine.