There are many kinds of urine tests that can be used to detect infection, to monitor various inflammatory illnesses resulting in pain, including gout and lupus, and to diagnose complications. These tests include:

• Uric acid test. Uric acid is the end product of the breakdown of nucleotides as a normal part of metabolism. In conjunction with urinalysis of other waste products, it can be used to assess how well the kidneys are functioning. It is a common diagnostic test for gout, a form of arthritis characterized by joint inflammation caused by excessive amounts of uric acid in the blood and deposits of excess uric acid crystals (urates) in and around the joints.
  
  
• Creatinine test. Measures the amount of creatinine in the urine. Creatinine is a waste product removed from the body by the kidneys. Abnormal amounts of creatinine may be a sign of kidney damage. Urinalysis for this waste product is commonly ordered in patients who have rheumatic diseases, such as lupus and scleroderma, to monitor for kidney damage.

Creatinine is sometimes checked with a creatinine clearance test. This compares results of a blood test to a 24-hour urine sample.

• Bilirubin test. Measures the amount of bilirubin – an orange-yellow waste product made from damaged or old red blood cells that have died – in the urine. Bilirubin is normally not detected in the urine. Excessive amounts of bilirubin can cause jaundice (yellowing of the skin and the whites of the eyes). The presence of bilirubin in the urine is often a sign of liver or gallbladder dysfunction, which can cause abdominal pain.
  
  

• Microalbuminuria test. Detects albumin, a protein that prevents fluid from leaking out of blood vessels, nourishes tissues and transports vitamins, hormones, drugs and ions throughout the body. Protein is not normally detectable in urine. The presence of protein in urine (proteinuria) is often an early sign of kidney disease. People with diabetes or certain rheumatic diseases, such as lupus and scleroderma, should be regularly tested for microalbuminuria for early detection and prevention of kidney damage.
  
  
• Nitrite test. Nitrite is normally not detectable in the urine. Nitrite is formed when bacteria changes nitrate in the urine into nitrite. The presence of nitrite in the urine (nitrituria) is often a sign of a urinary tract infection, which results in painful urination.
  
  
• Urine specific gravity test. Measures the concentration of particles in the urine. Abnormally increased or decreased urine specific gravity may indicate a kidney disorder.
  
  
• Urine pH test. Measures the pH (acidity) of the urine. A high level of urine pH may indicate a kidney disorder, including kidney failure.
  
  
• White blood cell test. Checks urine for the presence of white blood cells. The main infection-fighting cells in the body, white blood cells are not normally detectable in the urine. The presence of white blood cells in the urine may indicate a urinary tract infection or prostatitis.