Urinalysis Lab Terms

What is Urinalysis?

The analysis of physical and chemical properties of urine.

What types of factors affect the appearance and composition of urine?

Diet, level of physical activity (or inactivity), environmental conditions, or fluid intake.

What does the color of urine indicate?

• Urine varies in color from very pale yellow to a straw/amber color.

• Pale yellow = Excessive fluid intake but also may be a sign of diabetes insipidus

• Brighter yellow= High level of vitamins, especially B vitamins

• Pink to red tint = Caused by certain foods such as beets but may also be indicative of the presence of blood in the urine

• Straw to amber = May be a sign of dehydration resulting from fever or other illness

• Olive green to green tint = Caused by certain bacterial infections or the presence of bile pigments

• Brown to black tones = Signs of phenol or heavy metal poisoning. 

What does the clarity of urine indicate?

•  Regardless of color, urine is usually clear.

• Cloudiness of the sample may show excessive levels of white blood cells, fats, protein, or other mineral salts. Cloudiness may also indicate bacterial infection.

What does the Ph level of urine indicate? Include normal range and factors that affect it.

• Urine is normally slightly acidic but like many other qualities, many factors can affect the pH of urine at any given moment

• Generally the pH ranges from about 4.5 to 7.5.

• Decrease: Eating large quantities of meat; A consistently low pH may indicate diabetes mellitus. 

• Increase: Large amounts of vegetable matter; Excessively high pH for urine may indicate a bacterial infection but certain dietary supplements may lead to this condition as well.

What does the Protein level of urine indicate? Include normal range and factors that affect it.

• Little or no protein is typically found in urine as it is filtered out in the kidneys.

• Little protein Prescence = may show up due to factors ranging from stress to temporary dehydration

• persistent protein presence = Indicate kidney damage, specifically the glomerulus, a structure in the kidney that normally prevents protein from passing to the urine.

• Common causes of glomerular damage = long-term high blood pressure, untreated diabetes, autoimmune diseases, or bacterial infection. 

What does the Glucose level of urine indicate? Include normal range and factors that affect it.

• Also not typically found in urine as it is re-absorbed during processing in the kidneys.

• Increase: Diabetes mellitus may cause glucose levels in the body to reach levels higher than the kidneys are able to filter, resulting in a positive glucose test in urine.

• Both stress and eating a high carb meal may cause some glucose to appear temporarily but diabetes results in the persistent presence of glucose.

• Kidney damage may also cause the presence of glucose as the ability of the kidney to reabsorb glucose may be impaired.

What does the Ketone level of urine indicate? What causes ketones to form Include factors that affect its presence in the blood.

• Ketones = Result of fat metabolism.

• Cause: The need to burn body fat may result from starvation. Diabetics may not be able to regulate levels of insulin in the body which also may lead to ketones in the urine. However, strenuous exercise, alcoholism or pregnancy may also cause the presence of ketones. 

What does the Blood/hemoglobin level of urine indicate? How should you always treat blood/hemoglobin in the urine? Include factors that affect it to appear in the blood.

• The presence of blood and/or hemoglobin, while possible in the case of extreme physical activity or by taking certain medications, should always be treated as abnormal.

• Causes: liver or kidney damage, infection or damage in the urinary tract, a condition causing excessive red blood cell destruction, and kidney stones. 

What does the Bilirubin level of urine indicate? Include what it indicates when it is in the blood and its causes.

• Bilirubin = Normal product of the metabolism of hemoglobin but is not normally present in urine.

• Cause: When red blood cells are broken down, the hemoglobin released is recycled and a byproduct of the process is bilirubin. Bilirubin is formed in the liver and passed to the intestine for excretion.

• Indicate: Liver is not functioning to capacity, an excessive amount of red blood cells are being broken down.

• Causes: Cirrhosis, gall stones causing bile blockage, types of anemia, or traumatic injury to the liver or gall bladder.

What does the Nitrites level of urine indicate? Include what it indicates when it is in the blood and its causes.

• Indicate: Typically a sign of urinary tract infection as nitrite is not found in urine.

• Cause: Nitrates are produced in the body during food metabolism and certain bacteria can reduce nitrates to nitrites in the bladder or urinary tract.

What does the Specific Gravity level of urine indicate? Include what it indicates when it is in the blood, normal ranges and does this factor cause a false sense of security?

• Specific gravity: As the concentration of material in the urine increases, the specific gravity increases. An equal volume of a sample with more material, such as salts, protein, minerals, etc., would have a higher mass and therefore a higher specific gravity.

• A normal range for urine is 1.005 to 1.030.

• While specific gravity is useful, certain kidney disorders may result in the inability to concentrate urine properly so care should be taken to not allow a “normal” specific gravity value to lead to a false security.