Urine history, Composition, Normal Findings, Advantages of Urine Analysis

Urine history

History of the urine examination

1. Ancient Egyptian physicians used to taste the urine to find the disease.
2. Indian physicians started to use urine for the diagnosis of diseases in almost 2000 BC.
3. Greek physician Hippocrates also recognized the value of urine examination.
   1. He noted that the color, odor, and even taste of the urine helped in the diagnosis.
4. Then in the middle ages, urine examination also got important.
   1. They started measuring the specific gravity with a urinometer.
5. In the 19th century, with the invention of the microscope, urine examination started helping in the diagnosis of various diseases like hematuria and bacterial infection.
6. In the modern era, urine examinations diagnose diabetes mellitus, proteinuria, and ketone bodies.
7. The analysis of the urine is actually the beginning of laboratory medicines.
8. At that time, the physicians checked the urine’s gross appearance, like color, turbidity, odor, volume, and urinary infection.

9. They were testing the viscosity and even the sweetness. For sweetness, they were observing the attraction of the ants to urine.

10. Hippocrates wrote a book on urine examination as uroscopy in 5th BC.
11. In 1140 AD, color char was developed, describing the significance of 20 different colors of urine.
12. Chemical testing progressed after the ant gathered around the diabetic urine.
13. Later on, taste testing was also started.
14. In 1694, Frederick Dekkers discovered the protein, Albuminuria by boiling the urine.
15. Pisse prophets by the Charlatans became the subject of the book published by  Thomas Bryant in 1627.
16. The advent of the microscope in the 17th century led to the examination of urine sediments.
17. Richard Bright, in 1827 made the urine examination a routine for the patients.
18. In 1930 the number and the complexity of urine examinations made urine examination impractical.
19. With modern facilities, the urine examination is a routine part of the patient’s doctor’s office visit.

 Moderne urine examination:

1. Now urine examination is popular due to the following:
   • Easily available sample.
   • Urine gives much of the body’s metabolism information.
   • This information from the urine is cheap.
2. The National Committee for clinical laboratory standards (NCCLS) defines the urine analysis procedure as reliable, accurate, safe, and cost-effective.

Urine definition

1. Urine is a liquid biopsy obtained without pain or cost to the patient, but it provides a wealth of diagnostic information.
2. Urine is the main source of information from sick (damaged) kidneys to physicians.
3. Urine is the fluid excreted through the kidneys, passes through the ureter, and is stored in the urinary bladder. When the urinary bladder is full, it is discharged through the urethra.

In a normal healthy person, urine is:

1. Sterile.
2. Clear.
3. Amber color.
4. It is slightly acidic (pH 5 to 6).
5. Specific gravity is 1.024
6. It has a characteristic odor.
7. The daily output is 500 mL.
8. Anuria when the urine volume is <100 mL/24 hours.
9. Oliguria when the urine volume is <400 mL/24 hours.
10. Polyuria when the urine volume is > 2000 mL/24 hours.

Urine Composition

1. The kidneys continuously form the urine as an ultrafiltrate of the plasma. Reabsorption of the water and filtered substances are essential to the body’s function, converting roughly 170,000 mL of filtered plasma to the average daily urine output of 1200 mL.
2. Urea. It is produced in the liver by the breakdown of proteins and amino acids.
   1. This is 50% of the dissolved solid substances in the urine.
   2. Organic substances like creatinine and uric acid.
3. Inorganic substances. The major substance is chloride (CL¯), followed by Na+ and K+.
   1. The dietary intake makes it difficult to decide on the normal level.
4. Water.
5. Other substances found are:
   1. Hormones.
   2. Drugs.
   3. Vitamins.
   4. Cells.
   5. Cast.
   6. Crystals
   7. Bacteria.

Urine constituents depend upon the following:

1. Physical activity.
2. Dietary intake.
3. Body metabolism.
4. Endocrine functions.

To confirm the urine sample:

1. Advise urea and creatinine; these are present in high concentrations than any other body fluids and confirm that the specimen is urine.

The Urine analysis includes the following:

Physical properties include:

1. Color
2. Appearance (opaque or colorless)
3. Odor

Chemical Tests include:

1. pH
2. Specific gravity
3. Protein
4. Glucose
5. Ketones
6. Bilirubin
7. Urobilinogen
8. Blood
9. Nitrite
10. Leukocyte esterase

Microscopic Examination includes:

1. Red blood cells
2. White cells (WBC)
3. Casts
4. Crystals
5. Epithelial cells
6. Bacteria and other microorganisms

Normal Urine findings are :

• Please see the details in Urine Analysis Part 2.