Urinalysis test strips are useful diagnostics for the detection and monitoring of various diseases & health conditions.
In this article we will take you through the basics of urinalysis test strips and give you some advice on which strips the first time user should buy.
Article summary
- The kidney works to remove waste from the blood, and balance water, salts and minerals.
- Urine carries excess water, salts and minerals from the body.
- Understanding of the composition of urine helps us to gain inside into the health of the body.
- A urinalysis strip is a piece of plastic or paper which a number of chemical reagent pads on it
- The properties of a urine sample is found by comparing the colour of a reacted urinalysis test strip with a coloured grid on the strip's packaging
The importance of urine
Urine is a waste product of the body produced by the Kidney. The kidney filters blood by removing waste and balancing water, minerals and salts. Clean filtered blood is exits the kidney and circulates through the body.
Excess water, waste products and excess mineral and salts leave the kidney via the urinary tract, are stored in the bladder and then evacuated via the urethra.
By analyzing urine it is possible to understand the state of the body. The presence or absence of certain molecules, and the measurement of other properties can indicate potential health issues in the Kidney, Urinary Tract or elsewhere in the body.
Urinalysis is the 2nd most used diagnostic in the world. While there are many types of urinalysis in existence, in this article we are focusing on home urine tests done via a chemical dipstick. These urine dipsticks are useful because they are cheap, fast and effective.
Urinalysis test strips
Urinalysis test strips are pieces of plastic or waterproofed paper that have a number of absorbent pads soaked with different chemical reagents.
When a urinalysis test strip is dipped into a urine sample the chemically impregnated pads react with the urine. Dependent on the result of the chemical reaction certain interpretations about the properties of the urine can be interpreted.
Each pad on the urinalysis test strip has a different chemical reagent. It is possible to buy Urinalysis Dipsticks with only one reagent pad or to buy one with up to 12 reagent pads. The more pads there are, the more molecules or properties are being tested.
Some of the tests available for home urinalysis testing include:
- Leukocytes and nitrites to test for urinary tract infections (UTI)
- Red blood cells to test for bleeding or wounds in the urinary tract.
- pH, or the acid-base balance of urine
- Proteins which may be a sign of kidney damage
- Specific gravity which can give insight into the body's hydration
- Glucose which may be an indication of diabetes
Reading results
The results of a urinalysis test strip are based upon the color change of the chemical pads after they have reacted with the urine. These chemical reaction produce color changes in the reagent pads. This color change is visible to the human eye and a test result is determined by comparing the color of the reacted pad to a colored matrix on the Urine Strip packaging. Once the color on the dipstick has been matched to one in the matrix, the result is simply read off the packaging.
The procedure is therefore to fully dip and submerge the test strip in your urine sample, removed it and leave for the appropriate amount of time so a full reaction can occur. Once this has happened the colors can be compared to the colored matrix on the packaging and the results determined.
What measurements will I find?
The results of home urine tests fall into two categories: Qualitative and Semi-Quantitative.
A qualitative result is non-numerical and will generally show a “negative result”, meaning the compound is not present, “Trace” result, meaning there might be a low concentration of the molecule present, or a “Positive” result, meaning the compound is present.
Positive results are often shown on a scale of “+”’s such as +, ++, +++ etc. with each additional + indicating a higher concentration of the molecule.
A semi-quantitative result means a numerical value is given with its unit of measure. It is semi-quantitative because it is not a precise result but one with a range of error. Semi-quantitative results in Urinalysis Test Strips will often have more than one unit of measure given. This type of test shows the presence or absence of certain compounds and typically the compounds concentration.
Finally, some results such as Acid-Base balance or Specific Gravity give a result that measures this chemical property on a scale. For example Acid-Base balance uses the pH scale which runs from 1 to 14. A low result from 1 to 6 means the sample is acidic, 7, the sample is neutral, and a result greater than 7 the sample is basic (the term alkaline can also be used).
Another example is the specific gravity measure which is given as a ratio of the density of the urine sample versus the density of water. For example, a ratio of one (1) means the density of the Urine sample is the same as water, results above 1 means the sample is more dense than water, and vice versa for a sample less than 1. (see our article on using specific gravity to determine hydration here).
What does this all mean?
Doctors are trained to understand these results, the average patient not. For first time buyer and user of Urine Dipsticks it can be difficult to know what these results mean. We have also found that most first time users it is difficult to know which strip to buy. People using strips for the first time most often accept the recommendation from their doctor or their pharmacist, which is always a good place to start. That said, we have found that not all manufacturers make their strips easy to use for the average patient.
Some of the issues we have found with Urine Test Strips are that the majority are aimed at Doctors and trained medical professionals. This means that after completing a Urine Test that there is no information available to assist the user in interpreting the results. For a patient under the care of a medical professional, this is less of a problem as at the next visit the doctor can interpret the results for them. For patients with chronic conditions they will learn over time. For the first time user it will most likely require some internet research and an eventual visit to the doctor.
Those products which are aimed at patients are beneficial due to the diagnostic nature of the tests. Products like the Atlas Medical Home Test Kits allow users to obtain a diagnostic which is very useful. There are other kits, which we will not name, which do the same, but at a a very hefty price. The worst we have seen is a kit which sells two urine test strips for nearly 29 US dollars! This is nearly 100 times the price per strip if bought elsewhere. Clearly information asymmetry can lead to being ripped off.
How do I choose a strip?
We recommend that users start with a strip which has most, if not all, testing parameters available. Products like the Roche Combur 9 or Combur 10, and the Siemens Multistix 10SG, are perfect for this purpose. These strips have up to 10 assays that cover the vast majority of tests that can be done with a Urine Dipstick. By testing all these parameters and you can identify quickly if you have presence of any compounds that could indicate health problems and acts as a general health screen.
Another Consumer friendly test is the Roche Combur 5. We like this test as it has an easy to interpret 3 step qualitative scale starting with “0” for no presence and a 2 step “positive” scale with “+” and “++” results. The 5 parameters covered by the Combur 5 test cover the most usually tested parameters and can give insight into kidney and urinary tract health.
For users with an existing diagnosis using a Urine Dipstick with a wide range of assays can be beneficial as in addition to monitoring your known condition you can also monitor your general health and identify early onset of other issues which is an additional benefit if you are testing regularly anyhow.
Strips for Chronic Conditions
Strips for Periodic Conditions
Conclusion
Urinalysis Test Strips are incredible useful to screen, manage and prevent for a variety of health conditions however a new user of Urinalysis Test Strips can have a difficult time to select and then understand their results.
With some research and learning home urine testing can be mastered and can form an important part of your health record. Strips which offer no diagnosis to home urine test users are often cheaper but require more knowledge by the user. Strips which offer a diagnosis can be more expensive, but they do provide the peace of mind that comes with a clear diagnosis.
The Urinalysis Test Strip has been with us for decades now and will continue to be a useful tool. They are cheap, so if you haven’t already go to your local pharmacy and buy some. It will be a worthwhile experience.
