Urine blood reference range

On admission to a hospital; preparation for surgery; as part of a medical examination; or when evaluating a new pregnancy. It may be done if you have tummy or back pain, frequent or painful urination, or blood in the urine

Sample of urine (20-50 mls) in a sterile container; the first urine passed in the morning is preferred.

Urine for urinalysis however can be collected at any time. The first morning sample is the most valuable because it is more concentrated and more likely to demonstrate abnormal results if there is an underlying problem e.g. blood from bleeding in the urinary tract.

Because of the potential (particularly in women) to contaminate urine with bacteria and cells from the surrounding skin, it is important to first clean the genitalia. Men should wipe the tip of the penis; women should spread the labia of the vagina and clean from front to back. As you start to urinate, let some urine fall into the toilet, then collect a sample of urine in the container provided.

No test preparation is needed

On average it takes 7 working days for the blood test results to come back from the hospital, depending on the exact tests requested. Some specialist test results may take longer, if samples have to be sent to a reference (specialist) laboratory. The X-ray & scan results may take longer. If you are registered to use the online services of your local practice, you may be able to access your results online. Your GP practice will be able to provide specific details.

If the doctor wants to see you about the result(s), you will be offered an appointment. If you are concerned about your test results, you will need to arrange an appointment with your doctor so that all relevant information including age, ethnicity, health history, signs and symptoms, laboratory and other procedures (radiology, endoscopy, etc.), can be considered.

Lab Tests Online-UK is an educational website designed to provide patients and carers with information on laboratory tests used in medical care. We are not a laboratory and are unable to comment on an individual's health and treatment.

Reference ranges are dependent on many factors, including patient age, sex, sample population, and test method, and numeric test results can have different meanings in different laboratories.

For these reasons, you will not find reference ranges for the majority of tests described on this web site. The lab report containing your test results should include the relevant reference range for your test(s). Please consult your doctor or the laboratory that performed the test(s) to obtain the reference range if you do not have the lab report.

For more information on reference ranges, please read Reference Ranges and What They Mean.

This test identifies and measures some of the by-products of normal and abnormal metabolism, cells, cell fragments, and bacteria in urine. Urine is produced by the kidneys, which filter wastes out of the blood, help regulate the amount of water in the body, and conserve proteins, electrolytes, and other compounds that the body can reuse. Anything that is not needed is excreted in the urine.

Several diseases can be diagnosed in their early stages by detecting abnormalities in the urine. Abnormally high levels of glucose, protein, bilirubin, red blood cells, white blood cells, crystals, and bacteria can indicate disease. They may be present because:

1) There are elevated concentrations in the blood which spill over into urine
2) Kidney disease has made the kidneys less effective at filtering or
3) An infection has put bacteria and white blood cells into the urine .

A complete urinalysis consists of three distinct testing phases:

• Visual examination, which evaluates the urine's colour, clarity, and concentration;
• Chemical examination, which tests chemically for a number of substances that provide valuable information about health and disease; and
• Microscopic examination, which identifies and counts the type of cells, casts, crystals, and other components (bacteria, mucous ) that can be present in urine.

See below for details of these examinations.

Today, a routine urinalysis consists of the visual and the chemical examinations. Your urine may be examined under a microscope if there is an abnormal finding in one of the first two phases listed above or if your doctor specifically requests it.

Urinalysis is used as a screening and/or diagnostic tool because it can detect different metabolic and kidney disorders. Often, substances such as protein or glucose will begin to appear in the urine before patients are aware that they may have a problem. It is used to detect urinary tract infections (UTI) and other disorders of the urinary tract. In some conditions, urinalysis also provides an easy, economical, and relatively fast test to follow patient progress, for example, if you want to know whether a condition is getting better or worse. However, a urinalysis cannot detect all disorders.

A routine urinalysis may be done when you visit your doctor, when you attend the outpatient clinic or when you are admitted to the hospital. It may also be part of a routine medical examination, a new pregnancy evaluation, or preparation for planned surgery. A urinalysis will most likely be performed if you see your doctor complaining of tummy pain, back pain, painful or frequent urination, or blood in the urine. This test can also be useful in monitoring whether a condition is getting better or worse.

Urinalysis results can have many interpretations. Abnormal findings are a warning that something may be wrong and should be looked at further. Normal urinalysis results do not mean there is no illness. Urinalysis is only one screening test that can provide a general overview of a person’s health. Your doctor must look at the urinalysis results alongside your health complaints and other information available.

Urinalysis testing is frequently carried out by dip-stick testing in the clinic and results are available immediately. This is called near-patient testing or point of care testing (POCT). If there is an abnormal finding, such as excessive protein or the presence of blood, it may be necessary to send the sample on to the laboratory for further analysis. This will take several days and depending on the tests that need to be carried out.

Because this is a general screening test, this is usually not important and most of the time it is a random urine collection. However, if your doctor is looking for a specific finding, you may be asked to collect a sample at a specific time. For example, the presence of glucose is better looked for in a specimen collected after a meal, low levels of protein are better detected in a concentrated specimen collected first thing in the morning.

Some commercial testing strips can be purchased at a pharmacy to perform part of the chemical examination, such as urine pH, urine glucose, and urine ketones but the tests are best performed by someone who is used to reading and interpreting them.

• Pale yellow or colourless urine indicates dilute urine where lots of water is being excreted.
• Dark yellow urine indicates concentrated urine and the excretion of waste products in a smaller quantity of water, such as is seen with the first morning urine, with dehydration, and during a fever.

Urine clarity refers to how clear the urine is. Usually clarity of the urine is reported as: clear, slightly cloudy, cloudy, or turbid. “Normal” urine can be clear or cloudy. Substances that cause cloudiness but that are not considered unhealthy include mucus, sperm and prostatic fluid, cells from the skin, normal urine crystals, and contaminants such as body lotions and powders. Other substances that can make urine cloudy, like red blood cells, white blood cells, protein or bacteria, indicate a condition that requires attention.

Urine colour and clarity can be a sign of what substances may be present in urine. However, confirmation of suspected substances is obtained during the chemical and microscopic examinations.

• specific gravity,
• pH,
• protein,
• glucose,
• ketones,
• blood,
• leukocyte esterase,
• nitrite,
• bilirubin, and
• urobilinogen.

Some test strips also have a test pad for ascorbic acid (vitamin C).

New near patient testing devices (POCT) give a machine-readable result quantifying the concentration of some tests as mentioned above (e.g. glucose, specific gravity, bilirubin), and/or give positive or negative result.

The first test, specific gravity, is a measure of urine concentration and is measured using a chemical test. There are no “abnormal” specific gravity values. This test simply indicates how concentrated the urine is. Specific gravity measurements provide a comparison of the amount of substances dissolved in urine as compared to pure water. If there were no solutes present, the SG of urine would be 1.000 – the same as pure water. Since all urine have some substances dissolved, a urine SG of 1.000 is not possible. If a person drinks excessive quantities of water in a short period of time or gets an intravenous (IV) infusion of large volumes of fluid, then the urine SG may be as low as 1.002. The upper limit of the test pad, an SG of 1.035, indicates a concentrated urine.

pH is not generally a very helpful test. As with specific gravity, there are typical but not “abnormal” pH values. The kidneys play an important role in maintaining the acid-base balance of the body. Therefore, any condition that produces acids or bases in the body such as acidosis or alkalosis, or the ingestion of acidic or basic foods, can directly affect urine pH. Diet can modify urine pH. A high-protein diet or consuming cranberries will make the urine more acidic. A vegetarian diet, a low-carbohydrate diet, or the ingestion of citrus fruits will tend to make the urine more alkaline. Some of the substances dissolved in urine can precipitate out to form crystals when the urine is acidic, others can form crystals when the urine is basic. If crystals form while the urine is being produced in the kidneys, a kidney stone or “calculus” can develop. By modifying urine pH through diet or medications, the formation of these crystals can be reduced or eliminated. The pH can change and become less acidic if the urine is not tested within a few hours of collection. Therefore, samples to test pH should arrive the lab as soon as it is collected.

• Disorders that produce high amounts of proteins in the blood, such as multiple myeloma
• Infections of the urinary tract
• Conditions that destroy red blood cells
• Inflammation, malignancies (cancer), or injury of the urinary tract – for example, the bladder, prostate, or urethra
• the presence of blood in the urine perhaps due to stones which are damaging the walls of the kidney or bladder
• Vaginal secretions that get into and contaminate the urine

1. An excessively high glucose concentration in the blood, such as may be seen with people who have uncontrolled diabetes.
2. A reduction in the "kidney threshold". When blood glucose levels reach a certain concentration then the kidneys begin to excrete glucose into the urine. Sometimes the threshold concentration is reduced and glucose enters the urine sooner- at a lower blood glucose concentration.

Some other conditions that can cause glycosuria include hormonal disorders, liver disease, certain drugs, and pregnancy. When glycosuria occurs; other tests such as blood glucose are usually performed to further identify the specific cause.

Ketones are not normally found in the urine. They are intermediate products of fat metabolism. They can form when a person does not eat enough carbohydrates (for example, in cases of starvation or high-protein diets), or when a person’s body cannot use carbohydrates properly. When carbohydrates are not available the body metabolises fat instead to get the energy it needs to keep functioning. Ketones in urine can give an early indication of insufficient insulin in a person who has diabetes. Severe exercise, exposure to cold, and loss/lack of carbohydrates, such as with frequent vomiting, ketogenic diets or early morning fasting urine samples can also increase fat metabolism, resulting in ketonuria.

This test is used to detect haemoglobin in the urine (haemoglobinuria). Haemoglobin is an oxygen-transporting protein found inside red blood cells (RBCs). Its presence in the urine indicates blood in the urine (known as haematuria). The small number of RBCs normally present in urine (see microscopic examination) usually result in a “negative” test. However, when the number of RBCs increases, they are detected as a “positive” test result. Even small increases in the number of RBCs in urine can be significant. Numerous diseases of the kidney and urinary tract, as well as trauma, medications, smoking, or strenuous exercise can cause haematuria or haemoglobinuria. This test cannot determine the severity of disease nor be used to identify where the blood is coming from. For instance, contamination of urine with blood from haemorrhoids or vaginal bleeding cannot be distinguished from a bleed in the urinary tract. Therefore, it is important to collect a urine specimen correctly, and for women to tell their health care provider that they are menstruating when asked to collect a urine specimen. Sometimes a chemical test for blood in the urine is negative, but the microscopic examination shows increased numbers of RBCs. When this happens, ascorbic acid (vitamin C) many be checked because it can cause falsely low or negative test results.

Leukocytes are white blood cells (WBCs). Normally, a few white blood cells (see microscopic examination) are present in urine and this test is negative. When the number of WBCs in urine increases significantly, this screening test will become positive. When the WBC count in urine is high, it means that there is inflammation in the urinary tract or kidneys. The most common cause for WBCs in urine (leukocyturia) is a bacterial urinary tract infection (UTI), such as bladder or kidney infection.

This test detects nitrite and is based upon the fact that many bacteria can convert nitrate to nitrite in your urine. Normally the urinary tract and urine are free of bacteria. When bacteria find their way into the urinary tract they can cause a urinary tract infection (UTI). A positive nitrite test result can indicate a UTI. However, since not all bacteria are capable of converting nitrate to nitrite you can still have a UTI despite a negative nitrite test.

Bilirubin is not present in the urine of normal, healthy individuals. Bilirubin is a waste product that is produced by the liver from the haemoglobin of RBCs that are removed from circulation. It becomes a component of bile, a fluid that is secreted into the intestines to aid in food digestion. In certain liver diseases, such as biliary obstruction or hepatitis, bilirubin leaks back into the blood stream and is excreted in urine. The presence of bilirubin in urine is an early indicator of liver disease and can occur before clinical symptoms such as jaundice develop.

Urobilinogen is normally present in urine in low concentrations. It is formed in the intestine from bilirubin, and a portion of it is absorbed back into the bloodstream. Positive test results help detect liver diseases such as hepatitis and cirrhosis, and conditions associated with increased RBC destruction (haemolytic anaemia). When urine urobilinogen is low or absent in a patient with urine bilirubin and/or signs of liver dysfunction it can indicate the presence of hepatic or biliary obstruction.

A microscopic examination may or may not be performed as part of a routine urinalysis. It will typically be done when there are abnormal findings on the physical or chemical examination. It is performed on urine sediment – urine that has been centrifuged to concentrate the substances in it at the bottom of a tube. The fluid at the top of the tube is then discarded and the drops of fluid remaining are examined under a microscope. Cells, crystals, and other substances are counted and reported either as the number observed "per low power field" (LPF) or "per high power field" (HPF). In addition, some entities, if present, are estimated as "few," "moderate," or "many," such as epithelial cells, bacteria, and crystals.

Normally, a few RBCs are present in urine sediment. Inflammation, injury, or disease in the kidneys or elsewhere in the urinary tract, for example in the bladder or urethra, can cause RBCs to leak out of the blood vessels into the urine. RBCs can also be a contaminant due to an improper sample collection and blood from haemorrhoids or menstruation.

The number of WBCs in urine sediment is normally low. When the number is high, it indicates an infection or inflammation somewhere in the urinary tract. WBCs can also be a contaminant, such as those from vaginal secretions.

Normally in men and women, a few epithelial cells from the bladder (transitional epithelial cells) or from the external urethra (squamous epithelial cells) can be found in the urine sediment. Cells from the kidney (kidney cells) are less common. In urinary tract conditions such as infections, inflammation, and malignancies, more epithelial cells are present. Determining the kinds of cells present helps the doctor pinpoint where the condition is located. For example, a bladder infection may result in large numbers of transitional epithelial cells in urine sediment. Epithelial cells are usually reported as “few,” “moderate,” or “many” present per low power field (LPF).

In health, the urinary tract is sterile: there will be no microorganisms seen in the urine sediment. Microorganisms are usually reported as “none,” “few,” “moderate,” or “many” present per high power field (HPF). Bacteria from the surrounding skin can enter the urinary tract at the urethra and move up to the bladder, causing a urinary tract infection (UTI). If the infection is not treated, it can eventually move to the kidneys and cause pyelonephritis. Less frequently, bacteria from a blood infection (septicaemia) may move into the urinary tract. This also results in a UTI. Special care must be taken during specimen collection, particularly in women, to prevent bacteria that normally live on the skin or in vaginal secretions from contaminating the urine. A urine culture may be performed if a UTI is suspected. In women (and rarely in men), yeast can also be present in urine. They are most often present in women who have a vaginal yeast infection, because the urine has been contaminated with vaginal secretions during collection. If yeast are observed in urine, then tests for a yeast (fungal) infection may be performed on vaginal secretions. Trichomonads
Trichomonads are parasites that may be found in the urine of women or men (rarely). As with yeast, the trichomonads are infecting the vaginal canal and their presence is due to contamination. If these are found during a urinalysis, then follow-up testing for Trichomonas vaginalis may be performed to look for a vaginal infection.

Casts are cylindrical particles sometimes found in urine that are formed from coagulated protein secreted by kidney cells. They are formed in the long, thin, hollow tubes of the kidneys known as tubules and usually take the shape of the tubule (hence the name). Under the microscope, they often look like the shape of a “hot dog” and in healthy people they appear nearly clear. This type of cast is called a “hyaline” cast. When a disease process is present in the kidney, other things such as RBCs or WBCs can become trapped in the protein as the cast is formed. When this happens the cast is identified by the substances inside it, for example as a red blood cell cast or white blood cell cast. Different types of casts are associated with different kidney diseases and the type of casts found in the urine may give clues as to which disorder is affecting the kidney. Some other examples of types of casts include granular casts, fatty casts, and waxy casts. Normally, healthy people may have a few (0–5) hyaline casts per low power field (LPF). After strenuous exercise more hyaline casts may be detected. Cellular casts, such as RBC and WBC casts, indicate a kidney disorder.

• the urine pH is increasingly acidic or basic;
• the concentration of dissolved substances is increased; and
• the urine temperature promotes their formation

Crystals are identified by their shape, colour, and by the urine pH. They may be small, sand-like particles with no specific shape (amorphous) – or have specific shapes, such as needle-like. Some examples of crystals that can be found in the urine of healthy individuals include:

• amorphous urates
• crystalline uric acid
• calcium oxalates
• amorphous phosphates
• calcium carbonate

If the crystals are from solutes that are not normally in the urine, they are considered “abnormal.” Abnormal crystals may indicate an abnormal metabolic process. Some of these include:

When crystals form as urine is being made in the kidney, they may group together to form kidney “stones” or calculi. These stones can become lodged in the kidney itself or in the ureters – tubes that pass the urine from kidney to the bladder – causing extreme pain.

Medications, drugs, and x-ray dye can also crystallize in urine.