A urinalysis provides a lot of information about your kidneys and urine and can even indicate disease in other organs as well. If you have complaints of frequent or painful urination, blood in your urine, back or abdominal pain, a urinalysis may pinpoint where your complaints are coming from.
1. What is a urinalysis?
A urinalysis is a diagnostic test of your urine. You urinate into a sterile cup and the sample is sent to a laboratory for analysis.
2. Why does your doctor request a urinalysis?
If you have a chronic disease such as kidney disease, gout, or diabetes, your results will help clinicians know whether your disease is under control.
If you are going in for surgery or in the emergency room, this is an integral part of your evaluation.
A urinalysis is also commonly performed in annual wellness exams, an initial pregnancy visit, and follow-up throughout pregnancy.
3. What does a urinalysis detect?
A visual exam shows color, clarity or murkiness, and density. The laboratory part of the exam detects bacteria, white blood cells, red blood cells, epithelial cells, casts, glucose, ketones, protein, bilirubin, crystals and chemical markers suggestive of infection known as leukesterase and nitrites. Normally, the urine should be clear of these elements.
4. How are abnormal results interpreted?
Bacteria, white blood cells, leukesterase and nitrites are suggestive of a urinary tract infection.
Depending on what is found, certain diagnoses may be likely—although not necessarily definitive. For example, a high glucose level (or sugar) may be of concern and your doctor may order more definitive tests to see if you have diabetes. High protein levels, bilirubin, and red blood cells may be an early indication of kidney disease.
5. How should a urine sample be collected?
Your doctor will give you specific instructions on how to collect your urine so that only the urine is evaluated and it is not contaminated from outside your body. This will insure obtaining what is known as a “clean catch.”
If you are a woman, you will likely be given a sterile wipe to clean the inner lips of the vagina. Men will be asked to wipe the tip of the penis. You will be asked to urinate into the toilet for the first few seconds and then collect your urine in a sterile cup. This is called a “midstream urine sample.”
Samples taken shortly after you wake in the morning are the most concentrated. In some cases, you will be asked to collect your urine then, rather than later in the day.
6. Sources
Kreder KJ, Williams RD. Urologic laboratory examination. In: Tanagho EA, McAninch JW. Eds. Smith’s General Urology. 17th edition. 2008. New York:McGraw Hill.