The urine dipstick test analyzes components in a urine sample. The components of urine have normal and abnormal levels. Furthermore, there are components that do not belong in the urine, which would render abnormal results. Some components analyzed by the urine dipstick test include glucose, ketones, nitrite, leukocyte esterase, protein, bilirubin, pH and blood.
Glucose and Ketones
The nonpathologic cause of glucose in urine is renal glycosuria, a condition in which sugar excretes in the urine. In addition, glucose in the urine may be due to a kidney disease called Fancoli syndrome. On the other hand, ketones in the urine may result from a low-carbohydrate diet. Diabetes mellitus is a pathologic cause of glucose and/or ketones in the urine.
Nitrite and Leukocyte Esterase
The presence of nitrite and/or leukocyte esterase in the urine indicate urinary tract infection. Additionally, leukocyte esterase may indicate pelvic inflammation or problems with the kidney. However, fever may cause nonpathologic presence of leukocyte esterase. Nitrite always has a pathologic cause when present.
Protein
Nonpathologic causes of protein in the urine include exercise or fever. In addition, orthostatic proteinuria, the presence of protein due to body position, may be a benign cause. However, protein in the urine may be due to kidney disorders or urinary tract infection. Associated kidney dysfunction include glomerular or tubular disorders.
Bilirubin
The presence of bilirubin in the urine only has pathologic causes. Hepatitis and biliary obstruction are two causes. Hepatitis, the inflammation of the liver, may be due to a virus, alcoholism, toxins or autoimmune disorders. Often due to gallstones, blockage of a bile duct may lead to biliary obstruction.
pH
Diet has an affect on pH in the urine. A high-protein diet may render low pH urine and a low-protein diet may result in high pH levels. In addition, eating a meal can affect pH levels. However, not all pH levels equate benign causes. For example, acidosis may cause low pH levels. Urinary tract infection or renal dysfunction may render high pH levels.
Blood
The presence of blood in the urine does not necessarily have a pathologic cause. For females, menstruation could be one cause. In addition, catheterization and exercise are nonpathologic causes of blood in the urine. Notwithstanding, blood may indicate serious pathologic causes, such as kidney disorders, urinary tract infection, cancer and hypercalciuria (elevated calcium).
False Results
The urine dipstick test may render false readings. False results may be due to contamination, diet, fever, exercise and certain medication. If your physician suspects false readings, you may be asked to complete a follow-up test to confirm results.
References
- Pediatric Clinics of North America: The Abnormal Urinalysis
- Pedbase.org: Pediatric database - orthostatic proteinuria
- "Harrison's Principles of Internal Medicine"; Fauci, Braunwald, Kasper, Hauser, Longo, Jameson and Loscalzo; 2008
