The kidneys are important organs that remove excess fluid and toxic waste products from the body. They do so by filtering the blood and excreting noxious chemicals and molecules into the urine. Under normal circumstances, protein and blood are not found in the urine, as the kidneys retain them within their blood vessels. If you find protein and blood in your urine, it could be a sign of kidney disease.
Protein and blood in your urine can be detected using a test called a urinalysis. This test can measure the presence of both protein and blood, as well as detect the presence of bacteria and white blood cells, the cells that fight off infections. The kidney does not allow molecules as large as proteins to be filtered into the urine. Therefore the presence of protein in the urine, also called proteinuria, is an indication that either the glomeruli, the microscopic filtering units within the kidneys, or the tubules that carry blood throughout the kidney are damaged.
Some temporary causes for the presence of protein in the urine include fever and heat exposure. Conditions that cause persistently elevated protein levels in the urine include kidney infections, chronic renal failure, glomerulonephritis — an inflammation of the glomeruli — and high blood pressure. The causes of hematuria, or blood in the urine, include kidney infections, kidney stones, enlarged prostate, cancer, acute kidney disease and trauma.
Proteins are electrically charged molecules that attract fluid and help keep it within blood vessels. If the level of protein loss in the urine is large enough that it decreases the amount of protein in the bloodstream, fluid can leak out into the surrounding tissues, causing edema. This can result in swelling in the hands and feet and around the eyes, shortness of breath if fluid filters out into the lungs and abdominal pain. Blood in the urine can be a scary sight, although sometimes the blood loss is microscopic and can only be picked up by a urinalysis. Hematuria can be accompanied by abdominal or flank pain and pain on urination.
The treatment for the presence of protein and blood in the urine depends on the underlying cause. Kidney and bladder infections can be treated with oral or intravenous antibiotics. Patients with kidney stones need pain medicines until they pass the stone. Renal failure or glomerulonephritis need specialized treatment by a kidney specialist and may require a biopsy to identify the underlying condition.