What Is the Importance of Urinalysis?

Updated November 21, 2016

Urinalysis is an important diagnostic test used to determine certain conditions. Urine is collected and examined physically, chemically and microscopically. It may be ordered by your doctor along with other tests. The specimen may be a clean-catch sample, which is a midstream specimen, or a 24-hour urine collection, where it is collected for a full day.


Urinalysis is commonly used for the diagnosis of urinary tract infections and other urinary tract disorders. It can identify kidney disorders, confirm and monitor pregnancy. A urinalysis is routinely performed during an annual physical to identify early signs of disease, prior to surgery, and any time you are admitted to the hospital. The test can also identify the presence of excess protein, glucose and red blood cells which indicate the need for further evaluation, according to the American Association of Clinical Chemistry (AACC).


The physical examination of a urinalysis is done by checking the appearance and colour such as whether it is cloudy or clear and if it is a pale or dark yellow, according to the National Institutes of Health. Normal urine can be anywhere between nearly colourless to a dark yellow. The chemical examination is performed by using a chemical test stick that changes colours that can identify nine different substances. A microscopic examination can also identify issues, such as bacteria, mucus, urine crystals or other substances


Your doctor may specify when he would like you to collect your urine sample. Typically, the first morning urine is requested because the concentration is higher. Depending on what your doctor is looking for, you may be asked to collect it at a more specific time, such as following a meal, if he is checking glucose levels, according to AACC.


There is a wide variety of conditions, some of which are quite serious, that may be diagnosed through a urinalysis, according to the National Institutes of Health. Some of these include acute tubular necrosis, anorexia nervosa, atheroembolic renal disease, bladder stones, heart failure, diabetes, systemic lupus, malignant hypertension, ovarian cancer, prostate cancer, renal vein thrombosis, stress incontinence and urethral stricture.


Certain medications may alter the colour of your urine, such as iron supplements, chloroquine, nitrofurantoin, I-dopa, phenytoin, phenothiazines, riboflavin, triamterene and phenazopyridine. Your doctor may advise you not to take your medication prior to the test. Some foods may also change it to a reddish colour, such as blackberries or beets.


It is important to recognise that even if your urinalysis is normal, it does not necessarily prove that you do not have an illness. Some substances may not be released in elevated quantities in the early stages, or they may be released intermittently throughout the day. Therefore, one urine specimen may not detect a suspected condition. Other medical tests may be necessary.

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