urine Microscopic examination is a laboratory test used to examine the physical, chemical, and microscopic characteristics of urine. The test helps to detect any abnormalities in the urine, which may indicate underlying health conditions. The procedure involves analyzing a small sample of urine under a microscope, which allows the technician to view the cells, bacteria, crystals, and other substances present in the urine.
Explanation of Urine Microscopic Examination:
Urine microscopic examination is a laboratory test that analyzes a small sample of urine under a microscope to evaluate the physical, chemical, and microscopic characteristics of the urine. It helps to diagnose various health conditions, such as urinary tract infections, kidney disease, and bladder cancer. The test involves analyzing the color, clarity, pH, and specific gravity of the urine and identifying the type and number of cells, bacteria, and other substances present in the urine. Abnormal findings may indicate an underlying health condition.
Purpose of the Test:
Here are some of the purposes of urine microscopic examination:
- Diagnose Urinary Tract Infections (UTIs): The test is used to identify bacteria, white blood cells, and other substances that indicate the presence of a UTI.
- Diagnose Kidney Diseases: The presence of red blood cells, white blood cells, and other substances in the urine can indicate kidney damage or disease.
- Monitor Kidney Function: The test can be used to monitor the progress of kidney disease and assess the effectiveness of treatment.
- Screen for Bladder Cancer: Abnormal cells in the urine may indicate the presence of bladder cancer.
- Evaluate Kidney Stones: The presence of crystals in the urine can indicate the formation of kidney stones.
- Diagnose Metabolic Disorders: The presence of glucose, proteins, and other substances in the urine can indicate metabolic disorders such as diabetes or proteinuria.
- Monitor Pregnancy: The test can be used to monitor the health of pregnant women and identify potential complications such as preeclampsia.
- Evaluate Autoimmune Diseases: The presence of antibodies in the urine can indicate autoimmune diseases such as lupus or glomerulonephritis.
Overall, urine microscopic examination is a versatile and useful diagnostic tool that can provide important information about the health of the urinary system and the presence of various health conditions.
Why get Tested:
Here are some reasons why urine microscopic examination may be ordered by a healthcare provider:
- To diagnose a urinary tract infection (UTI)
- To diagnose kidney disease
- To monitor kidney function
- To screen for bladder cancer
- To evaluate kidney stones
- To diagnose metabolic disorders, such as diabetes or proteinuria
- To monitor the health of pregnant women and identify potential complications
- To evaluate autoimmune diseases, such as lupus or glomerulonephritis
- To monitor the effectiveness of treatment for various health conditions
- To assess the risk of kidney damage from certain medications or medical conditions
- To evaluate the health of the urinary system in people with chronic conditions, such as hypertension or diabetes
- To identify potential kidney problems in people with a family history of kidney disease
- To assess the risk of developing kidney disease in people with risk factors, such as high blood pressure or diabetes.
Overall, urine microscopic examination is a useful diagnostic tool that can provide valuable information about the health of the urinary system and the presence of various health conditions. It can help healthcare providers make an accurate diagnosis, monitor the progress of treatment, and identify potential complications.
When to get Tested:
Here are some situations where a healthcare provider may order a urine microscopic examination:
- If a person is experiencing symptoms of a urinary tract infection (UTI), such as painful urination, frequent urination, or blood in the urine.
- If a person is experiencing symptoms of kidney disease, such as swelling in the legs, fatigue, or high blood pressure.
- If a person is being monitored for kidney disease, to assess the progress of the disease or the effectiveness of treatment.
- If a person has risk factors for kidney disease, such as high blood pressure, diabetes, or a family history of kidney disease.
- If a person is being monitored for bladder cancer, to assess the effectiveness of treatment or to screen for recurrence.
- If a person has a history of kidney stones or is experiencing symptoms of kidney stones, such as pain in the back or side.
- If a person is pregnant and needs to be monitored for potential complications, such as preeclampsia.
- If a person is being evaluated for an autoimmune disease, such as lupus or glomerulonephritis.
- If a person is being monitored for the effects of certain medications on the kidneys.
- If a person is being evaluated for a metabolic disorder, such as diabetes or proteinuria.
Overall, a urine microscopic examination may be ordered in various situations where a healthcare provider needs to assess the health of the urinary system or diagnose certain health conditions.
Sample Required for Microscopic Examination:
The sample required for a urine microscopic examination is a midstream clean-catch urine sample. Here are the steps for collecting this type of sample:
- Wash your hands thoroughly with soap and water.
- Clean your genital area with a cleansing wipe or towelette provided by your healthcare provider. Wipe from front to back to avoid contaminating the sample with bacteria from the anus.
- Start to urinate into the toilet bowl.
- After a few seconds, place a sterile collection cup under the stream of urine. Be careful not to touch the inside of the cup with your hands.
- Collect about 30 to 60 milliliters of urine, or the amount specified by your healthcare provider.
- Remove the cup from the stream of urine and finish urinating into the toilet bowl.
- Replace the lid on the collection cup.
- Wash your hands thoroughly with soap and water.
- Label the collection cup with your name, date of birth, and the date and time of the collection.
- Deliver the sample to the laboratory or healthcare provider as soon as possible. If you can’t deliver it immediately, store it in the refrigerator until you can.
Overall, collecting a clean-catch urine sample is important to ensure that the sample is not contaminated with bacteria from the genital area, which could affect the accuracy of the results of the microscopic examination.
Type of urine samples:
- Random sample:
This is a diluted urine sample and may give an inaccurate interpretation of patient health. But is best to do microscopy to evaluate WBC or RBC.
- First Morning sample:
This is the best sample for microscopy and urine analysis. This is the concentrated urine because of urine remained throughout the night in the urinary bladder. This will contains an increased concentration of analytes and cellular elements. Urine must have remained in the bladder for 8 hours is considered as the first-morning sample.
- Urine for sugar (Postprandial 2 hours):
Postprandial 2 hours sample collected after 2 hours of high carbohydrate diet.
- Midstream clean catch urine:
This sample is needed for the culture and sensitivity of urinary infection. The patient is advised to clean the urethra, then discard the first few mL of urine. Now midstream of the urine is collected in the sterile container.
- 24 Hours of a urine sample
- In this case, discard the first urine and note the time.
- Now collect urine in the container for 24 hours and put the last sample in the container.
- Refrigerate the sample.
- This 24 hours samples are needed for measuring urea, creatinine, sodium, potassium, glucose, and catecholamines.
- Suprapubic collection of the urine sample:
This is done in the patients who cannot be catheterized and the sample is needed for culture. This sample is collected by the needle.
- Catheter collection of urine:
This is done by patients who are bedridden and can not urinate.
- Pediatric urine sample:
In infants, special collection bags are made adherent around the urethra. Then urine is transferred to a container.
Microscopic Examination tests:
The following are some of the tests that may be included in a urine microscopic examination:
- Urine sediment analysis: This test involves examining a urine sample under a microscope to look for cells, bacteria, crystals, and other substances that may indicate a urinary tract infection or other health condition.
- Red blood cell (RBC) count: This test measures the number of red blood cells in a urine sample, which may be elevated in cases of kidney stones, bladder cancer, or other urinary tract disorders.
- White blood cell (WBC) count: This test measures the number of white blood cells in a urine sample, which may be elevated in cases of urinary tract infections or other inflammatory conditions.
- Epithelial cell count: This test measures the number of epithelial cells (cells from the lining of the urinary tract) in a urine sample, which may be elevated in cases of bladder cancer or other urinary tract disorders.
- Bacteria and yeast culture: This test involves growing bacteria or yeast from a urine sample to identify the specific type of microorganism causing an infection.
- Crystals analysis: This test involves identifying crystals that may be present in a urine sample, which can provide information about the pH and composition of the urine and may indicate the presence of kidney stones or other urinary tract disorders.
- Casts examination: This test involves examining a urine sample under a microscope to identify casts (structures made of proteins or other substances), which may be present in cases of kidney disease or other urinary tract disorders.
Overall, the specific tests included in a urine microscopic examination may vary depending on the healthcare provider’s reason for ordering the test and the patient’s individual health situation.
Significance of Urine Microscopic Examination:
The significance of a urine microscopic examination includes:
- Detecting Urinary Tract Infections: A urine microscopic examination is used to detect the presence of bacteria, white blood cells, and other indicators of a urinary tract infection.
- Evaluating Kidney Function: The test can help to identify the presence of casts, red blood cells, and other substances in the urine, which can be useful in evaluating kidney function.
- Diagnosing Certain Kidney Disorders: Urine sediment analysis can detect the presence of proteins, casts, and other substances that may indicate certain kidney disorders, such as glomerulonephritis.
- Monitoring Certain Medical Conditions: The test can be useful in monitoring certain medical conditions, such as diabetes, which can affect kidney function and urine composition.
- Detecting Pregnancy: A urine microscopic examination can detect the presence of hCG, a hormone produced during pregnancy, which can confirm the presence of a pregnancy.
- Assessing Urinary Tract Stones: The test can detect the presence of crystals, which may indicate the formation of urinary tract stones.
Overall, a urine microscopic examination is a valuable diagnostic tool that can provide important information about a person’s urinary tract health and kidney function. The test can be used to detect and diagnose a variety of medical conditions, monitor treatment progress, and help healthcare providers make informed treatment decisions.
Normal Urine Findings:
Here is a table of normal urine findings:
|Color||Pale or yellow|
|Volume||1200 to 2000 ml/24 hours|
|pH||5 to 7|
|Specific gravity||1.001 to 1.035|
|Cast (hyaline)||0 to 5 / HPF|
|Red blood cells||≤ 3 / HPF|
Rarely 2 to 3 RBCs/HPF
|White blood cells|| ≤2 to 5 HPF|
Male = 1 to 2 /HPF
Female = 0 to 5 /HPF
|Squamous epithelial cells||≤ 15 to 20 / HPF|
|Glucose|| Random sample = Negative|
24 hours sample = 1 to 15 mg/dL
|Ketones||Urine = Negative|
|Bilirubin||Negative (o to 0.02 mg/dL)|
Random sample= <1 mg/dL
2-hour sample = <1 mg /2 hours
24- hours sample = 0.5 to 4.0 mg/dL
|Albumin||10 to 100 mg /24 hours|
|Protein||Quantitative = negative|
Urine 24 hours sample:
Adult male = 1 to 14 mg/dL
Adult female = 3 to 10 mg/dL
Child <10 years = 1 to 10 mg/dL
|Calcium||Normal diet = 100 to 300 mg/24 hours|
Low-calcium diet = 50 to 150 mg/24 hours(Another source = 0.3 g/24 hours)
|Sodium chloride||average 10 g /24 hours|
Patient with moderate to severe salt depletion = <10 mmol/L or <20 mmol/L /24 hours(Another source = 15.0 g/24 hours)
|Sodium||Adult = 40 to 220 meq/24 hoursChild = 41 to 115 meq/24 hours|
|Potassium||Adult = 25 to 125 meq/ 24 hours|
Child = 10 to 60 meq/24 hours(Another source = 3.3 g/24 hours)
|Magnesium||75 to 150 mg/24 hours(Another source = 0.1 g/24 hours)|
|Creatinine||Male = 20 to 28 mg/Kg/24 hours|
Female = 15 to 21 mg/Kg/24 hours(Another source = 1.5 g/24 hours)
|Urea nitrogen||5 to 15 g/24 hours|
|Nitrogen||7 to 20 g/24 hours|
|Urea||10 to 35 g/24 hours(Another source = 25.0 to 35.0 g/24 hours)|
|Uric acid||With normal diet = 250 to 750 mg/24 hours|
With purine-free diet = <400 mg/24 hours
With high-purine diet = <1000 mg/24 hours(Another source = 0.4 to 1.0 g/24 hours)
|Urobilinogen||0.2 to 4.0 mg/24 hours|
|Chloride||Adult = 110 to 250 meq/24 hours|
Child: <6 years = 15 to 40 meq/24 hours
Child: 10 to 16 years = 64 to 176 meq/24 hours
Advantages and Limitations of the test:
Advantages of urine microscopic examination include:
- Non-invasive: Urine collection is a non-invasive procedure that can be easily performed in a healthcare setting.
- Wide Range of Applications: Urine microscopic examination can be used to detect a variety of medical conditions, including urinary tract infections, kidney disease, and pregnancy.
- Quick Results: Results of the test are usually available within 24-48 hours, allowing for prompt diagnosis and treatment.
- Cost-effective: Compared to other diagnostic tests, urine microscopic examination is relatively inexpensive.
- Useful in Monitoring Treatment: The test can be used to monitor the effectiveness of treatment for urinary tract infections, kidney disease, and other medical conditions.
Limitations of urine microscopic examination include:
- False Negative Results: The test may fail to detect certain medical conditions, particularly in cases of early-stage disease or low bacterial counts.
- False Positive Results: The test may produce false positive results in cases where there is contamination of the urine sample or the presence of non-pathogenic bacteria.
- Limited Specificity: The test may not provide specific information about the type of bacteria or other microorganisms causing an infection.
- Limited Diagnostic Value for Some Conditions: The test may not be helpful in diagnosing certain medical conditions, such as some forms of kidney disease.
- Variable Accuracy: The accuracy of the test may be affected by a variety of factors, including the timing of urine collection, the storage and handling of the sample, and the expertise of the healthcare provider performing the test.
In conclusion, a urine microscopic examination is a useful diagnostic tool that provides important information about a person’s urinary tract health and kidney function. The test is non-invasive, cost-effective, and has a wide range of applications, including the detection and diagnosis of urinary tract infections, kidney disease, and pregnancy. However, it is important to keep in mind the limitations of the test, such as the possibility of false positive or negative results and limited diagnostic value for certain conditions. Healthcare providers must carefully consider the results of a urine microscopic examination in conjunction with other clinical data to make an accurate diagnosis and develop an effective treatment plan for their patients.
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