Urine Lab Tests
All You Need to Know About Urine Tests

There are quite a number of urine lab tests or urine tests that can be done to help provide information on what is going on in the body. They include urinalysis, urine pregnancy test, urine STI tests and more. See all the common tests here and what each of these mean. You would be able to post any question you have and get help too.

What Are Urine Lab Tests?

Urine lab tests

Changes in our body chemistry affects our kidneys early and can be detected in our urine before any of such changes can show up in our blood.

There are quite a number of urine lab tests or urine tests that can be done to help provide information on what is going on inside your body.

These tests could be anything from a simple urine test done by dipping a test strip into a freshly collected urine sample (referred to as urinalysis), to tests done over hours and days by more complex systems in the laboratory.

Urine tests are used to check for a variety of abnormalities, including:

  • Presence of infection in our kidney, ureter or bladder
  • Detection of abnormal type or amount of protein leakage in the urine
  • Confirmation of pregnancy
  • Excessive glucose in the urine
  • Detection of Blood in the urine even when not visible to the naked eye
  • Presence of different kinds of blood cells, or chemicals that come from the breakdown of substances like muscle
  • Detection of illegal drugs, alcohol, and products of elimination and breakdown of your medication
  • Kidney damage.

Are you having a urine test ordered and wondering why you have been asked to do it? Or are you just looking for information on the various types of urine tests out there? Whatever it is that brought you here, be sure that we would provide you with most information you want to find out on urine tests.

Why Would My Doctor Order A Urine Test?

Urine tests can be done for many reasons. It may be as a result of some symptoms you told your doctor about, which could include:

  • Pain with urination
  • The urge to urinate frequently
  • The feeling that you can’t control your urinary urges
  • Fever and back pain, which may indicate an infection in your kidneys
  • Pain and lower abdominal pain, which could indicate a bladder infection.
  • You may have missed your menstrual period, and your doctor may be testing for pregnancy

Other reasons for urine tests include the following:

  • You may have symptoms of diabetes, which include the need to urinate frequently and to drink a lot of liquid because you constantly feel thirsty.
  • You may have already been diagnosed with diabetes, which can cause a lot of damage to your kidneys. Your doctor may be testing for protein, which indicates kidney damage, or for glucose, which indicates your blood sugar is too high.
  • There are other chemicals that spill into your urine if they are not eliminated the right way, either because of malfunctioning kidneys or because of excess levels. These chemicals can include amylase, which is a chemical found in the pancreas. It is also found in the glands that produce your saliva. If these glands are blocked, the amylase may spill into your urine.
  • If your kidneys are damaged, protein, which should not be in your urine, may spill over into the urine as a result of damage.
  • If you have a shortage of sodium in your blood, or potassium, important electrolytes, your doctor may check to see if these things are spilling out through your kidneys at a high rate, instead of being preserved to keep your cells in balance.
  • If you are drunk or if you seem “out of it,” your doctor may take a test of your urine to see if you have been abusing drugs or alcohol. Usually, if the police think there is something like that wrong with you, they will also ask that your urine be tested.
  • Your doctor may be checking to be sure that the medications you are taking are being “metabolized” by the body correctly, because the breakdown products of some medications are found in the urine.
  • Your doctor may look at your urine under a microscope to see if there are signs of infection, like white blood cells and bacteria. Sometimes you doctor may find signs of a sexually transmitted disease.
  • There is a new test for prostate cancer that can be done by testing your urine.
  • The crystals that cause gout can be found in urine.

Commonly Requested Urine Tests and What They Mean

The following are the commonly requested urine lab tests and what they mean:

1. URINALYSIS

Urinalysis is one of the most commonly done urine test in the world.Urinalysis is one of the most commonly done urine test in the world.

This is certainly the most frequently requested urine test anywhere in the world. Urinalysis simply means, urine analysis.

It is the testing of a freshly passed urine sample for the presence of substances that may indicate the presence of infection, or bladder or kidney problem.

Urinalysis is done by:

  • Passing urine into a clean small container and tested within 1 hour of sample collection
  • A test strip which contains different chemical agents on different parts of the strip is dipped into the urine sample and removed as quick as possible so as not to dissolve the reagent on the strip into the urine container.
  • The reagent or test strip is then held for about 30 seconds and any color change on the strip is observed.
  • The strip is then placed on the side of the test strip container to compare the observed color changes (if any) with those on the strip container to determine what changes have occurred.
  • The reading of the changes on the test strip is no longer valid or reliable after 3-5 minutes of being dipped in the urine.
  • Urinalysis testing offers a very reliable way of testing for presence of infection and changes in blood chemistry as well as kidney issues as revealed in the urine. 
  • Urinalysis generally have a positive predictive value of 95% - meaning that in 19 out of 20 times, the test is reliable. It also means that in 1 out of 20 times, if the test suggests that you do not have a urine or bladder infection, that may not be true.

So what are the things that are being looked out for in urinalysis and what do they mean?

  • Color of Your Urine. The laboratory report will report the color of your urine, and if it is cloudy or not. The color can often be changed by what you eat or drink. If you eat foods like beets or rhubarb, your urine may turn red. Blood in your urine can make it red or brownish colored. If you have a crush injury, your urine may be red, but it will not have any red blood cells in it. Vitamin supplements can change the color of your urine. If you are dehydrated, your urine will be a stronger color than if you are drinking a lot of water.
  • Leucocyte esterase (LEU). Leucocytes means white blood cells. Normally, our urine should contain no white blood cells. In urinary tract infection, the chemical on the test strip would change from white or pale yellow to purple if there is presence of an enzyme released by white blood cells, also called leucocytes esterase. The degree or depth of the purple color registered on the test strip would determine if there is a mild (small), moderate, or severe (large) amount of infection presence in the urinary tract. 
  • Nitrite (NIT). This is the break down product from a number of bacteria types. It is derived from those types of bacteria that can break down urine or the ammonia in urine into nitrite. Not all bacteria do this. So the presence of nitrite in a urine test along with leucocyte esterase is very very indicative of a urinary tract infection. Nitrite would be absent in infection caused by any Gram-positive bacteria or Pseudomonas species.
  • Urobilirubin (URO). Presence of positive urobilirubin or bilirubin would mean that there is excessive blood break down as could be found in tumor or cancers of the kidney, liver disease, or certain blood disorders.
  • Protein (PRO or ALB). Presence of significant amount of protein or Albumin in urine testing could mean excessive leakage of protein from the blood through the kidney as in acute or chronic kidney disease, pre-eclampsia, nephrotic syndrome and some inflammatory diseases affecting the kidney. Protein or albumin could be found in some patient’s urine in small quantity when they stand for a long time or following fever or insect bite or bladder infection.
  • pH. pH in urine helps tell if your urine is alkaline or acidic. High pH urine is an alkaline urine and can be seen with the use of certain medications and low pH urine can be seen in diabetic ketoacidosis. Normal pH is between 4.5 to 8.0.
  • Blood (BLO). Urine test strips are able to detect the presence of small amount of free hemoglobin in urine at a fraction of those not visible to the naked eye. The presence of blood in urine could be due to contamination from local injury, menstruation in a lady, or bladder infection, kidney infection, bladder or ureter or kidney stone or cancer. If you are found to have unexplained blood in your urine, it is usually a trigger to do more tests to exclude potentially serious causes of blood in urine. The presence of blood in the urine should always be investigated further.
  • Ketones (KET). Ketones are the break down products from fat metabolism. Starvation or prolonged fasting, vomiting or dehydration, and presence of diabetic ketoacidosis would all lead to the presence of ketones in the urine. If you have heavy load of ketones in your urine, you would require immediate medical attention and possibly admission for intravenous fluid administration. If you are diabetic and you are found to have heavy amount of ketones in your urine plus high amount of sugar level, this is an emergency situation that could be life threatening.  You would require immediate hospitalization and treatment. If you are a pregnant and have high amount of ketones in your urine from severe morning sickness (hyperemesis gravidarium), you would require immediate hospitalization and administration of intravenous fluids.
  • Glucose (GLU). This is sugar. Sugar should normally not be found in our urine. The presence of sugar in urine could indicate diabetes or glucose leak from the kidney without diabetes, as can be seen in some pregnant women and individuals.
  • Microscopy. Urinalysis is often accompanied by microscopy especially if this test is done in a laboratory. This involved the examination of a small sample of the urine under the microscope. Things that could be found in such urine microscopy include blood cells, bacteria, casts, cells, and parasites in some cases.

Urinalysis urine lab test is a gift to medicine. Many doctors are now able to do this test within a few minutes in the consulting room while seeing a patient and be able to glean very useful information that helps in reaching diagnosis and treatment of the patient in an efficient manner.

2. URINE PREGNANCY TEST

  • This is the second most common urine lab test or urine home test.
  • It is a test to determine if a woman is pregnant
  • Though any urine sample can be used to do this test, an early morning urine – the first urine passed on waking up in the morning, is best for a urine pregnancy test.
  • Urine is collected into a small sample container from which a drop or so is taken by means of a micro-pipette and dropped into the pregnancy test kit or pregnancy test kit is immersed into the urine sample, depending on type
  • The test kit reader is allowed to stand for about two minutes
  • The test kit is then examined for the presence of two lines, which would indicate a positive test (meaning you may be pregnant) or one line only which would indicate a negative result (meaning you may not be pregnant).

3. URINE TEST FOR CHLAMYDIA AND GONORRHEA

  • There is now a very rapid and reliable testing for chlamydia and gonorrhea that can be done from a urine sample
  • You collect the very first 30milliliter or so of urine and this is sent to the lab and tested
  • You should be able to get the result within a few hours or a few days
  • It is very common for people to be able to test themselves for chlamydia and gonorrhea by ordering the home urine test kit for STI.

4. URINARY MICROALBUMIN TEST (UMALB) OR
    ALBUMIN CREATININE RATIO (ACR)

  • This is a test commonly done in patients with diabetes or high blood pressure to help detect the presence of abnormal leakage of protein from the kidney.
  • Normally, albumin, which is a protein produced by the liver and found in the blood is never filtered through a healthy kidney.
  • In very early stages of kidney disease, albumin can leak through the kidney filtration system, leading to its been found in the urine.
  • A ratio of albumin and creatinine, which is another substance produced by muscles and excreted as waste can be calculated to determine the percentage of leakage.
  • A value greater than 2.99 indicates kidney damage (very very early stages) and may warrant treatment depending on the degree or severity.
  • Vigorous exercise before testing, presence of immune disease or high concentration of cholesterol in the blood can lead to the abnormal readings.
  • You would be asked to collect a small amount of urine which can be examined within 4 hours of collection and tested alongside your blood.
  • If the test is abnormal, you would be called in by your doctor and told the result.
  • Presence of abnormal ACR indicates what doctors refers to as CKD or chronic kidney disease. This could be very very early changes in the kidney which is not uncommon as we age and may not require any treatment or intervention.
  • High levels of ACR (usually greater than 30) may require treatment. Sometimes, treatment may be instituted way earlier than this level (>3).
  • Treatment often involve the use of a certain type of blood pressure lowering medication referred to as ACE inhibitor as well as optimal control of your blood sugar levels.

5. URINE CALCIUM LEVEL

  • This is a test where urine collected over a 24-hour period into a jar is tested for the amount of calcium in it.
  • It is usually done to investigate abnormal level of calcium in blood and urine which can result from over consumption of calcium in food or as supplement, bone and calcium metabolic disease, or kidney stones.
  • Normal values are between 2.5 - 7.5 mmol/day.

6. URINE CORTISOL LEVEL

  • Urine cortisol test is used to ascertain the presence of overactive adrenal gland.
  • This urine lab test is usually done by collecting urine for a full 24-hour period and then taken to the lab and tested.
  • A normal urine cortisol level is anything between 100 to 400 nmol per 24hour.
  • Severe stress (stress leads to production of cortisol), obesity, depression and alcohol abuse can all lead to abnormally high levels of cortisol in the urine, as is an overactive adrenal gland.
  • Other conditions that can lead to high levels of urinary cortisol levels include polycystic ovarian syndrome, pregnancy, certain cancers of the testicles, and some pituitary tumors.

7. URINE FREE CATECHOLAMINES

  • If your doctor suspects that you have a tumor of the adrenal gland referred to as phaechromocytoma, or nerve tumor like neuroblastoma, he or she might request that you have your urine free catecholamines tested along with your vanillylmandelic acid (VMA) level.

8. OTHERS

Other urine lab tests often done include:

  • Urine creatinine clearance level – to check for how much of creatinine is being excreted by your kidney in relation to the amount of creatinine in your blood to determine kidney function.
  • Urine total protein excretion – this is another urine test requiring the collection of urine over a 24hour period and tested for the amount of protein being excreted.
  • Urine Protein Electrophoresis – this is a urine lab test done to help differentiate the type of protein in urine, especially if a bone marrow tumor in suspected. A type of protein referred to as Bence Jones protein, if detected could mean that the patient has multiple myeloma or Waldenström's macroglobulinemia.

How Should I Prepare for My Urine Lab Test?

You usually do not need any significant preparation before having a urine test done. It is also usually not necessary to fast before doing any urine test.

Your doctor will tell you what foods or medicine to avoid, if any.

You can do your urine test if you are having your menstrual period, but be sure to let your doctor know that you were bleeding during the time of test so as not to cause a panic, as the blood would show in your urine.

You must be sure to clean around the urethra (in the genital area) before collecting the specimen for your urine lab tests.

In many cases, a mid-stream urine would be required – that is, you pass the first few ml of urine and then catch the middle part of your urine before it stops.

If you are testing for STI like gonorrhea or Chlamydia, the first flow of your urine (first 30 ml) is what is required for best result.

When Would I get The Result of My Urine Test?

Urine tests are often very quick to run. In most cases – like if having a urinalysis done in your doctor’s office, you should get the result of the test within 2 to 5 minutes.

If this is done in the lab, it may take a few days, depending on how soon the lab is able to communicate the result to your doctor.

References:

  • Practical Considerations for the Measurement of Free Light Chains in Serum. Tate JR et al. Clin Chem. 2003; 49(8): 1252-1257.
  • American Congress of Obstetricians and Gynecologists: "Routine Tests in Pregnancy
  • Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
  • Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
  • Retrieved from http://www.webmd.com/prostate-cancer/news/20110803/urine-test-may-help-predict-prostate-cancer December 13, 2013
  • Get Your Urine Test Interpreted
  • Did you just have a urine lab test done? Not sure what it means? Post any question you may have regarding a urine test here and get help with understanding what it means.


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