The Use Of Urinalysis In The Diagnosis Of Medical Conditions

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Overview

Urinalysis can simply be explained as an analysis of urine to diagnose and manage a wide range of medical conditions or disorders such as diabetes, urinary tract infections and kidney problems. 

It involves three stages – 

• Physical or macroscopic examination, 
• Microscopic examination, and 
• Chemical analysis.

The physical analysis involves examining the urine sample with the naked eyes to check for appearance, colour, clarity, foaming and turbidity. 

The microscopic examination involves the use of a microscope to examine the urine. To do this, you examine a small amount of urine with the aid of a microscope to check the urine contents that are not visible to the naked eyes. The urine is examined to check to detect foreign or unusual organisms. 

The chemical analysis is done using a dipstick. A dipstick is a plastic stick embedded with chemical strips. It is dipped into the urine and observed for colour change. A colour change indicates the presence of the substance above the normal. Some of the chemicals it screens for include – acidity, protein, bilirubin, red blood cells, white blood cells and glucose. 

Why you may be asked to run a urinalysis test.

These include 

• General check-up: you may be required to carry out a urinalysis test as part of your routine medical exam. 
• To screen or diagnose a medical condition: certain symptoms like frequent urination, abdominal pain, painful urination, back pain, presence of urine in your blood or other health issues related to urinary may warrant carrying out a urinalysis test to detect the exact cause and treatment method.
• It is also used to screen for a variety of disorders like liver disease, diabetes, and kidney disease.
• To monitor a medical condition: those suffering from urinary tract infection or kidney disease may be required to carry out a urinary test on a regular basis to monitor the condition and the treatment. 
• Other reasons a urinalysis test can be conducted are for pre-surgery operation or routine pregnancy check-up

Preparing for a urinalysis test

Before going for a urinalysis test there are certain precautions you must observe. 

Take plenty, but not an excessive amount, of water before carrying out the test. This is to help you produce urine for your test. However, this should be done an hour or two before the test time to prevent an adverse effect on the test. Thereby, giving false results. 

Discuss with your physician if you are on any medication at all. Some medications such as antibiotics, may meddle with the analysis and give false results. 

For a woman, discuss with your doctor if you are on your menstrual period.

Procedures for urinalysis

You will be given a bottle at the doctor’s office to put some urine into. In most cases, you can produce the urine sample at any time. However, in certain cases, you may be required to produce early morning urine, as it has a high-level concentration, usually less contaminated and has a higher chance of detecting abnormalities. 

At times, you may be required to produce clean catch urine. What this means is that you clean the genital area before producing the urine to prevent bacteria and cells from the surrounding skin from contaminating the urine sample and giving a false interpretation of the results.

It is best advised to pass out some of the urine into the toilet before collecting into the tube. 

The testing procedure for urinalysis and results interpretation.

After producing the urine, it is analysed in three ways – physical or macroscopic, microscopic and chemical analysis. 

Physical or macroscopic

The urine’s appearance is examined. Typically, urine is clear. Therefore, turbidity or cloudiness and an unusual odour may be an indication of a problem, such as an infection.

The colour of the urine is also taken note of. A colour other than the traditional colour of urine is an indication of an abnormality.  For example, red or brownish looking urine is an indication of the presence of blood in the urine. Greenish colouration or cloudy is an indication of bacterial infection. Foamy urine may be an indication of kidney disease. 

Microscopic examination

For the microscopic examination, a few drops of urine are viewed with the aid of a microscope to check for the presence of usual and unusual contents and the level. Some of the things looked out for are

• The presence of white blood cells (known as leukocytes) may be an indication of an infection.
• The presence of red blood cells (known as erythrocytes) may signal a blood disorder, a kidney disease or an entirely different underlying medical condition, such as bladder cancer.
• The presence of bacteria cells or yeasts is a probable indication of an infection.
• The presence of casts (tube-shaped proteins) may be a result of kidney disorders.
• The presence of crystals, which may have formed from chemicals in urine may be an indication of kidney stones.

Presence of epithelial cells, which may indicate a tumour.

Chemical examination

This is done using a dipstick (a thin, plastic stick fixed with strips of chemicals on it). The dipstick is placed into the urine to detect abnormalities through a colour change in the chemical strips. This indicates the presence of certain substances above their normal level. 

This dipstick test procedure checks for:

• Acidity (same as pH): This indicates the amount of acid present in the urine. Abnormal pH levels are an indication of a kidney, urinary tract infection or any other condition.
• Specific gravity (or concentration): A measure of specific gravity shows how concentrated particles in your urine are. A concentration higher than normal is often a result of not drinking enough fluids.
• Protein: this is one of the important building blocks in the body. Everyone has it in the blood, where it should be under normal circumstances. A healthy kidney plays the role of cleansing by removing waste product and extra water from the body. It doesn’t filter protein. However, when the kidney is damaged or dysfunctional, protein leaks to the urine. Thus, the presence of protein in the urine is an indication that the kidney’s filtering units are damaged.

However, the presence of low levels of protein in urine is normal but high amounts may indicate a kidney problem.

• Glucose: ordinarily, the amount of glucose in the urine is too low to be detected. Any detection, therefore, of glucose by this method usually calls for follow-up testing for diabetes. High glucose content is a marker for diabetes.
• Ketones: detection of ketones in the urine, no matter how small, could be an indication of diabetes and requires further testing.
• Bilirubin: This is the end product of red blood cell breakdown. Routinely, it is transported by the blood and passes into your liver, where it is removed and becomes part of bile. Therefore, the presence of bilirubin in your urine may indicate liver dysfunction which could be a result of liver damage or disease.
• Blood: The presence of blood in the urine may be a sign of kidney damage, kidney or bladder stones, kidney or bladder cancer, infection, blood disorders or certain illnesses. This, however, requires further testing for a proper and full diagnosis.
• White blood cells: detection of white blood cells is a sign of either an infection or an inflammation. This could be in the kidneys or anywhere along the urinary tract.
• Nitrites: This signal presence of an infection with certain kinds of bacteria.

The duration of the test procedure

The test usually takes about an hour or two. After which the doctor calls you into his office and discusses the findings with you. If any disease was diagnosed, he walks you through it and gives you the detailed information. Also, if there are follow analysis to be carried out the doctor will let you know.