Urine Analysis:- Part 4 – Urine Chemical Examination and Interpretations

Urine Chemical Examination

What sample is needed for the urine analysis?

1. Preferably use freshly voided urine.
2. If there is a delay, then refrigerate the urine.
3. The morning sample is concentrated urine.

What are the precautions for urine analysis?

1. Preferably examine the urine within the first 30 minutes.
2. Reject unlabelled urine sample.
3. Avoid fecal or menstrual blood contamination.

What does urine chemical examination include?

1. Urine protein.
2. Glucose.
3. Ketone bodies.
4. Bilirubin.
5. Urobilinogen.

 Protein in the Urine:

How will you define normal urine protein?

1. A normal, healthy person will have a daily protein exertion of 100 mg/day. This is a very small proportion of the total plasma protein.
2. Because of its smaller size, it is mostly albumin, with a small fraction of globulin as well.
3. The proximal tubules reabsorb most of the protein filtered in the glomerular filtrate.

What is the mechanism of proteinuria?

1. As a result of increased filtration from the glomerulus.
2. Or it is decreased reabsorption from the tubules.

Urine analysis, Proteinuria mechanism

4. Proteinuria is the first indicator of renal disease.
5. The random sample is negative.

What are the types of proteinuria?

1. Prerenal proteinuria:
   1. Nonrenal diseases cause this and is transient; it is seen in:
   2. Hemoglobinuria.
   3. Myoglobinuria.
   4. Acute phase proteinuria.
   5. This is usually not detected by the routine urine reagent strips.
2. Renal proteinuria:
   1. This is due to renal diseases involving glomeruli or tubules.
   2. Albumin appears in the urine in glomerular damage, followed by the WBCs and RBCs.
   3. It is seen in:
   4. SLE.
   5. Streptococcal glomerulonephritis.
   6. Strenuous exercise  (reversible condition).
   7. Pre-eclampsia and hypertension. (reversible condition).
   8. Toxic heavy metals.
   9. Severe viral infection.
3. Postrenal proteinuria:
   1. Proteins can be added as the urine passes through the ureter, urinary bladder, and urethra.
   2. Bacterial and fungal infection of the lower urinary tract,
   3. Menstrual contamination also contains proteins.
   4. Prostatic fluid and spermatozoa.

How will you define Orthostatic or postural proteinuria?

1. This is a persistent benign condition frequently seen in young patients.
2. It appears when the person is upright and disappears when the patient lies down.
3. Procedure to confirm the diagnosis:
   1. These patients are advised to empty their bladders before going to bed.
   2. Take the first urine sample when patients get up.
   3. Take another sample when patients are upright for several hours.
      1. The first sample will be negative.
      2. The second sample will be positive in orthostatic proteinuria.

How will you discuss Microalbuminuria?

1. This is seen in diabetic nephropathy.
   
2. This microalbuminuria indicates diabetic complications.
3. The further complications of diabetes can be prevented by controlling diabetes.
4. This is also associated with an increased risk of cardiovascular diseases.
5. Microalbuminuria is reported as albumin excreted as µg/min or in mg/24 hours.
6. The level is significant from 20 to 200 µg/min Or 30 to 300 mg/24 hours.
   1. In these cases, the albumin/creatinine ratio is >3.4 mg/mmol.
   2. The first-morning specimen is recommended.

How will you define Bence Jones proteinuria (BJ)?

1. It is seen in multiple myeloma patients.
2. These are monoclonal light-chain immunoglobulins.
3. This is a low molecular weight protein and is excreted in the urine.

How will you detect BJ protein?

1. Heat the urine, and these proteins coagulate at 40 to 60 °C.
2. Dissolve when the temperature reaches 100 °C.
   1. Reading the result: Urine turbid at 40 to 60 °C and clear at 100 °C is considered positive.

Urine analysis, Urine BJ protein test

How will you classify proteinuria?

What is the normal urine protein?

1. In 24 hours of urine, 150 mg or 20 mg/dL ( another source = 0 to 0.1 gm).
2. Another source:  Protein in the urine is <10 mg/dL or 100 mg/24 hours.
   1. This protein consists mainly of low-molecular-weight serum proteins, so the major protein is the albumin seen in the urine.
   2. Other proteins include serum and tubular microglobulins, Tamm Horsfall protein produced by the tubules, and proteins from the prostate and vaginal secretions.

How to check proteinuria?

Urine strips:

1. These are mostly used to screen for proteinuria. These strips are specific for albumin.
2. False-positive results are seen in the following:
   1. In alkaline urine.
   2. In highly buffered urine.

How will you perform a reagent test strip test for protein in the urine?

Urine protein reagent strips

What are the tests used to detect urine protein?

What are the clinical types of proteinuria and its etiology?

Glucose in the urine:

What is the significance of glucose in the urine?

1. Because of the diagnosis of diabetes mellitus, a glucose test in the urine is very commonly advised.
2. The blood glucose and urine glucose tests are part of a routine check-up.
3. Early diagnosis of diabetes mellitus helps improve the prognosis and complications of diabetes mellitus.

Write briefly glucose metabolism?

1. The proximal convoluted tubules almost all absorb glucose filtered in the glomerular filtrate; therefore, there will be a negligible amount of glucose in the urine.
2. Tubular absorption of glucose is an active process that depends upon the body’s needs.
3. In diabetes mellitus, tubular glucose transport ceases, and glucose appears in the urine.

Urine Glucose and the Role of Kidneys

4. In hyperglycemia, the tubular transport of glucose stops, and glucose starts appearing in the urine.
5. To test for diabetes mellitus, take it after 2 hours of the meal.
   1. The first-morning sample does not give a real picture of the last evening meal. Void the first sample and then collect the next sample.
   2. The renal glucose threshold is 160 to 180 mg/dL.

What is the normal glucose in the urine?

1. A random sample is negative (qualitatively, it is negative).
2. In 24 hours, urine glucose is 0 to 0.3 grams.
3. Another source, glucose in random urine, is <30 mg/dL.
4. Glucose in urine during pregnancy is called gestational diabetes.
   1. This is usually seen around the 6 months of pregnancy.
   2. Hormones secreted by the placenta during pregnancy are believed to block insulin’s action and lead to hyperglycemia.

What is Renal glycosuria?

1. It is seen when the blood glucose level is normal and glucose appears in the urine.
   1. Renal tubules’ absorption of glucose by the tubules is compromised.
   2. It is usually seen in end-stage kidney diseases, osteomalacia, and Fanconi’s syndrome.
2. Glucose false tests are seen in urine with a high specific gravity and a large amount of ascorbic acid.

What are the causes of Hyperglycemia of nondiabetic origin?

1. It is seen in the following conditions:
   1. Pancreatitis.
   2. Pancreatic cancer.
   3. Acromegaly.
   4. Cushing’s syndrome.
   5. Hyperthyroidism.
   6. Pheochromocytoma.
   7. The above conditions produce hormones like glucagon, epinephrine, cortisol, thyroxine, and growth hormone.
   8. These hormones act against insulin and lead to glycogenolysis.

Urine nondiabetic hormones

How will you check Glucose in the urine?

1. Reagents strips, glucose oxidase reaction.
2. Copper reduction method.

How will you describe Glucose-oxidase reagent strips?

1. This test is specific for the β-isomer of glucose.
   1. It converts glucose in the presence of oxygen to gluconic acid and hydrogen peroxide.
   2. The serum glucose concentration is proportional to the oxygen consumed in the reaction or the H2O2 produced.
   3. In the second step, peroxidase catalyzes the reaction between H2O2 and chromogen to form the oxidized colored compound, indicating the presence of glucose in the urine.
2. The result is reported as follows:
   1. Trace, 1+, 2+, 3+, 4+
   2. These colors also provide quantitative measurements ranging from 100 mg/dL to 2000 mg/dL or 0.1% to 2%.

Urine analysis: Glucose-oxidase principle

Chemical Examination of Urine by Glucose Oxidase Method

How will you perform the Copper reduction method (Benedict’s reaction)?

1. This test was used in the early days.
2. An alkaline cupric sulfate solution oxidizes all reducing sugars, such as glucose, galactose, fructose, maltose, xylulose, arabinose, and ribose.
   1. It forms a brick-red to yellow precipitate of Cu₂O.
3. This test involves reducing copper sulfate (CuSO4) to cuprous oxide in the presence of an alkali and heat.
   1. The color depends upon the amount of Cu₂O.
4. Reading:
   1. The color changes from blue = Negative (CuSO4).
   2. Green, yellow, orange/red = Positive 4+ (CuO).
   3. Greenish = 1+ to Yellow = 4+
   4. The positive reaction of 1+ = Roughly 50 mg/dL.
   5. The positive reaction of 4+ = 2 or more g/dL.

What is the principle of Benedict’s reaction?

Benedict’s reaction principle

Procedure for Benedict’s Reaction

How will you compare Benedict’s reaction and the Oxidase method?

Ketones Bodies in the urine:

How will you define ketone bodies in the urine?

1. Ketone bodies are absent in the normal person.
2. These are seen in patients with uncontrolled diabetes mellitus.
3. These can also be seen in person on a low carbohydrate diet.
4. These are seen in people on a high-fat diet.

Chemical examination of urine: ketone bodies metabolism and their presence in diabetic patients

What are the causes of the ketone bodies?

1. Diabetic acidosis.
2. Starvation.
3. Vomiting.
4. Malabsorption syndrome.
5. Pancreatic disorders.
6. Insulin dosage monitoring.
7. Strenuous exercise.
8. Inborn error of amino acid metabolism.

What are the types of ketone bodies?

1. Acetone.
2. Acetoacetate.
3. β-hydroxybutyric acid.

Ketone bodies formation

4. Ketone bodies are not normally found in urine because all the metabolized fats are completely broken down to CO2 and H2O.
5. When the carbohydrate energy source is unavailable, body fat stores are mobilized to supply energy, and ketones are found in the urine.
6. Ketone body formation in diabetic patients:
   1. In diabetic patients, ketonuria shows a deficiency of insulin.
   2. Adjusting the dose of insulin in diabetic patients is needed.

Ketone bodies in diabetic patients

7. The increased amount of ketones in the blood leads to electrolyte imbalance and dehydration.
8. If this is not corrected, it leads to acidosis, and ultimately, the patient goes into a coma.

ketone bodies in diabetes mellitus

9. These ketone bodies’ ratios differ: acetoacetate 20%, acetone 2%, and β-hydroxybutyrate 78%.

Ketone body formation and ratio

What is the normal ketone bodies in the urine?

1. These are negative in the random sample.
2. Qualitatively, it is also negative.

Urobilinogen in the urine:

How will you define urobilinogen in the urine?

1. It is a colorless compound that forms in the intestine by the bacterial enzyme from the reduction of bilirubin action.
2. Normal urine contains small traces of urobilinogen.
3. Because of fewer intestinal bacteria, infants have decreased urobilinogen in the urine.
4. It is decreased after antibiotic therapy because of the reduced number of intestinal bacteria.
5. Urobilinogen is a bile pigment like bilirubin, and hemoglobin degradation forms it.
6. It is formed in the intestine from the bilirubin by the action of the intestinal bacteria.
7. Most of the urobilinogen is reabsorbed into the blood circulation (enterohepatic circulation), and some of this is excreted through the kidney into the urine.
8.  It is oxidized to urobilin in the feces and gives a characteristic brown color to stool.
   1. So, usually, a urine test for urobilinogen is positive. The urine normally contains <1 mg/dL or Ehrlich unit. So, testing for bilirubin and urobilinogen is necessary to diagnose liver diseases.
9. Absent urobilinogen in the urine and feces is diagnostic of biliary duct obstruction.

What are the indications for urobilinogen in the urine?

1. Early detection of liver diseases.
2. Hemolytic diseases.
3. Hepatitis and Cirrhosis.
4. In carcinomas.

What sample is needed to test the urobilinogen in the urine?

1. A fresh urine sample is needed (because it is light-sensitive).
2. An ideal sample for detecting or quantitating is a 2-hour early afternoon specimen.
3. Keep in mind the diurnal variation.

What will the position of Urobilinogen be in different conditions?

Differential diagnosis of urobilinogen in the urine:

The fate of Urobilinogen and excretion in the urine

How will you perform the Ehrlich aldehyde reaction for urine?

1. This is the test for urobilinogen.
2. Perform this test on the fresh urine sample because it is unstable and breaks down into urobilin while keeping the urine.
3. This test detects urobilinogen at least at the level of 0.1 mg/dL.
4. What is the procedure for the Ehrlich aldehyde reaction?
   1. The reagent strip is impregnated with p-dimethylamino benzaldehyde and an acid buffer.
   2. This method may give a false-positive result due to the presence of porphobilinogen.
5. Another method uses the Diazonium compound, and it forms a red color.
   1. Result:  Red color in positive cases.

What is the normal urobilinogen in the urine?

1.  Its level with this method is 0.1 to 1.0 mg/dL.
2. The 2 mg/dL level is the cut-off point for the result to be abnormal.
3. These are 0 to 4 mg /24 hours.
4. Random urine = 0.1 to 1 Ehrlich U/dL or <1 mg/dL.
   1. 2 hours urine = 0.1 to 1.0 Ehrlich U/2 hours or <1 mg/2 hours.
   2. 24-hour urine = 0.5 to 4.0 Ehrlich U/24 hours or 0.5 to 4.0 mg/24 hours.

What are the causes of Increased levels of urobilinogen in the urine?

1. Hemolytic anemia.
2. Pernicious (megaloblstic) anemia.
3. Malarial attack.
4. Excessive bruising.
5. Pulmonary infarction.
6. Cirrhosis.
7. Acute hepatitis.
8. Cholangitis.

What are the causes of a decreased level of urobilinogen in the urine?

1. Complete or partial obstruction of the biliary tract.
2. Cholelithiasis.
3. Biliary duct inflammation.
4. Cancer of the head of the pancreas.
5. Antibiotic therapy will suppress intestinal bacterial flora.

Bilirubin in the urine:

How will you define bilirubin in the urine?

1. Bilirubin in the urine is called bilirubinuria.
2. This will appear in the urine before the appearance of jaundice.
3. Bilirubin is a pigmented yellow compound, a degradation product of hemoglobin.
4. The following diagram explains how bilirubin is formed. When production is increased, it may appear in the urine.

Bilirubin metabolism

5. Conjugated bilirubin appears in the urine when the normal degradation cycle is disrupted by obstruction of the bile duct, such as gallstones or cancer.
   1. Another possibility is when the liver cells are damaged, which allows the leakage of bilirubin directly into the circulation.
   2. Hepatitis and cirrhosis are common causes of liver cell damage and result in bilirubinuria.
6. Increased hemolysis does not produce bilirubinuria.
7. Bilirubin in the urine is detected only if the urine sample is fresh because bilirubin decomposes rapidly in bright light.
8. If the urine is left in the lab, bilirubin is converted into biliverdin, a green compound by the light not detected by the bilirubin strips.

What is the normal bilirubin level in urine?

1. Urine bilirubin is negative (0 to 0.2 mg/dL (0 to 0.34 µmol/L).
2. Bilirubin can be detected in urine by the Foam test.

How will you perform the foam test for bilirubin in the urine?

1. Place a small urine volume in the test tube, cap it, and shake it vigorously.
2. Result:
   1. The foam at the top is white, which means bilirubin is negative.
   2. If the foam is orange in color, it means bilirubin is present.

What are the other methods to detect bilirubin in the urine?

1. Diazo reaction is in the form of tablets or dipsticks.
2. Fouchet’s test.
3. Ferric chloride test.

How will you compare Fouchet’s, Ferric chloride, and Diazo’s reactions for Bilirubin?

What are the causes of Increased bilirubin in the urine?

1. Hepatitis and liver diseases.
2. Obstructive biliary tract disease.
3. Liver or biliary tract tumors.
4. Septicemia.
5. Hyperthyroidism.

Hemoglobinuria:

What are the causes of Hemoglobinuria?

1. It may result from the hemolysis of RBCs in the urinary tract, which occurs in dilute and alkaline urine.
2. This can also occur in intravascular hemolysis, where hemoglobin filters out through the glomeruli. No RBCs will be seen in the urine.

What is the pathogenesis of hemoglobinuria?

1. Under normal conditions, the hemoglobin+haptoglobin complex can not filter out of the glomeruli.
2. This happens when the free hemoglobin exceeds the haptoglobin, e.g.
   1. Hemolytic anemia.
   2. Transfusion reactions.
   3. Infection.
   4. Severe burns.
   5. Strenuous exercise.
   6. Malarial infection.

What is the normal hemoglobinuria?

• This is negative.

Myoglobinuria:

How will you define myoglobinuria?

1. Myoglobin is a heme-containing protein found in muscle tissue.
2. This is seen in the case of rhabdomyolysis.
3. The heme portion of myoglobin is toxic to the renal tubules; an increased concentration can lead to renal failure.
4. The blood hemolytic transfusion reaction may cause damage to the kidneys and lead to renal failure.

What are the causes of Causes myoglobinuria in the urine?

1. Crush syndrome.
2. Muscle wasting diseases.
3. Trauma.
4. Alcoholism.
5. Convulsion.
6. Extensive exertion.
7. Heroin abuse.

How will you summarize hemoglobinuria and myoglobinuria?

How will the Ammonium sulfate (NH4)2SO4) concentration test be performed?

1. It is done to differentiate hemoglobinuria and myoglobinuria:

Urine ammonium sulfate test for the D/D of hemoglobinuria and myoglobinuria

Phosphorus in the urine:

How will you define Phosphorus in the urine?

1. Most of the body’s phosphorus is combined with the calcium in the bones.
2. About 15% is present in the blood, making the main intracellular anions.
3. The human body contains 620 g of phosphorus, mainly in the form of phosphate.
4. The urine HPO₄-2^_: H2PO4^– ratio varies widely, from 1: 100 at pH 4.5 to 90:10 at pH 8.0.
5. Urine for phosphorus for 24 hours collections needs acid-washed detergent-free containers.

What are the indications for urinary 24-hour phosphorus?

1. In hyperparathyroidism.
2. In hypoparathyroidism.
3. In case of renal loss.

What are the functions of Phosphorus in the body?

1. It has a role in glucose and lipid metabolism.
2. It helps in the storage and transfers the energy in the body.
3. It generates bony tissue.
4. It maintains the acid-base balance in the body.

What is the normal phosphorus in urine?

1. Serum level = 2.4 to 4.1 mg/dL (0.78 to 1.34 mmol/L).
2. Urine = 1 gram /24 hours.
3. This also depends on the diet.
4. Inorganic phosphate = 20 to 40 meq/L.

Creatinine/Creatine in the urine:

How will you define creatinine in the blood and urine?

1. Creatine is synthesized in the liver, pancreas, and kidneys from the amino acids arginine, glycine, and methionine.
2. It is transported from blood to muscles, the brain, and other organs,  converted to phosphocreatine, and acts as an energy reservoir like ATP.
3. Creatinine is the waste product of creatine and phosphocreatine.
4. Most of the creatinine is produced in the muscles, proportional to the muscle mass.
5. Creatinine enters the blood and is excreted through the kidney.

What are the indications for creatinine in the urine?

1. To evaluate kidney diseases.
2. During 24- hours of urine collection, refrigerate the urine, and no preservative is needed.

What is normal creatinine in urine?

1. 1.0 to 1.6 gm/24 hours.
2. Or 15 to 25 mg/ kg body weight/24 hours.

Nitrites/Nitrates in the urine:

How will you define Nitrites/Nitrate in the urine?

1. Some of the bacteria from the urinary tract convert Nitrates into nitrite.
2. Bacteria containing the enzyme reductase will convert nitrate to nitrite.
   1. NO3 →NO2 in the presence of a reductase enzyme.
   2. This test is negative in yeast and gram-positive bacteria.

What is the mechanism of conversion of nitrite to nitrate?

1. The reductase enzyme is found in gram-negative bacteria like Enterobacteriaceae.
2. This is available as urine reagent strips and detects urinary tract infections.
3. Most infections start in the urinary bladder, and from there, it travels to the ureters, tubules, and renal pelvis and reaches the kidneys.
4. This is useful for detecting the initial urinary bladder infection called cystitis.
5. Cystitis will lead to pyelonephritis as a complication of cystitis, and the result is:
   1. Renal tissue damage.
   2. Impairment of renal functions.
   3. Hypertension.
   4. Sometimes, it leads to septicemia.
6. So, detection of bacteriuria in the early stages and timely treatment will prevent all these complications.

What are the Indications for Nitrate test?

1. Cystitis.
2. Pyelonephritis.
3. Monitoring of the patients who are at high risk for urinary tract infection.
4. Monitoring of antibiotic therapy.
5. Screening of the urine culture specimens.
6. These are negative.
   1. A negative result does not rule out bacteriuria.
7. A gram-positive pathogen does not produce a nitrate-reducing substance like:
   1. Staphylococcus.
   2. Enterococcus.
   3. Streptococcus.

Sodium in the urine:

How will you define sodium in the urine?

1. Sodium is the primary regulator for retaining or excreting water and maintaining acid-base balance.
2. Sodium also maintains the normal electrolytes’ intracellular and extracellular balance.
3. This will take place along with potassium under the effect of aldosterone.

What are the Indications for urinary sodium?

1. Electrolytes imbalance.
2. Acute renal failure.
3. Hyponatremia.
4. Oliguria.
5. Na⁺ excreted for diagnosis of renal and adrenal imbalance.
6. No preservative is needed for the collection for 24 hours; only refrigerate during the collection.

What are the causes of increased sodium in urine?

1. Addison’s disease (adrenal failure, primary and secondary).
2. Renal tubular acidosis.
3. Diabetic acidosis.
4. Tubulointerstitial disease.
5. Salt-losing nephritis.
6. Barrter’s syndrome.

What are the causes of decreased urinary sodium?

1. Excessive sweating and diarrhea.
2. Prerenal azotemia.
3. Cushing’s syndrome.
4. Primary aldosteronism.
5. Congestive heart failure.
6. Nephrotic syndrome with acute oliguria.

What is the normal sodium in urine?

1. Adult = 40 to 220 meq/24 hours urine (40 to 220 mmol/day)
2. Child = 41 to 115 meq/24 hours urine (41 to 115 mmol/day)
3. Value is dependent on salt intake.

Potassium in the urine:

How will you define Potassium in the urine?

1. Potassium acts as a body buffer system and plays an important role in maintaining electrolyte balance.
2. The potassium study is helpful for the study of renal and adrenal disorders.
3. Potassium in the urine is in the form of KCL, K2SO4, and K2PO4 salts.
4. K⁺ values <20 meq/L are associated with nonrenal causes.
   1. K⁺ >20 meq/L are associated with renal causes.

What are the indications for K⁺ estimation in the urine?

1. To evaluate the electrolyte imbalance.
2. Renal disorders.
3. Adrenal glands disorder.
4. No preservative is needed for urine collection for 24 hours; only refrigerate the sample during collection.

What is the normal potassium in urine?

1. Adult = 25 to 125 meq/24 hours urine (25 to 125 mmol/day).
2. Child = 10 to 60 meq/24 hours urine (10 to 60 mmol/day)
3. Values are diet-dependent.

What are the causes of increased urinary K^+?

1. Diabetic and renal tubular acidosis.
2. Primary renal diseases.
3. Cushing’s syndrome.
4. Starvation.
5. Primary and secondary aldosteronism.
6. Fanconi’s syndrome.
7. The onset of metabolic alkalosis.

What are the causes of decreased urinary K^+?

1. Addison’s disease.
2. In patients with K⁺ deficiency.
3. Pyelonephritis and glomerulonephritis.

Calcium in the urine:

How will you define Calcium in the urine?

1. The parathyroid gland hormones maintain calcium hemostasis.
2. An adequate amount of calcium is excreted in the stool, and a small amount is in the urine.
3. Calcium absorption is dependent upon dietary calcium intake.

What are the indications for calcium in the urine?

1. To evaluate the calcium intake.
2. To assess the rate of absorption from the intestine.
3. To find resorption from the bone.
4. To evaluate the renal loss.

What is the normal calcium in urine?

1. Normal diet = 100 to 300 mg/24 hours (2.50 to 7.50 mmol/day)
2. Low calcium diet = 50 to 150 mg/24 hours (1.25 to 3.75 mmol/day)
3. Another source:
   1. 5 to 12 meq/L
   2. < 150 mg/ 24 hours on a low-calcium diet.
   3. Or o.3 g/24 hours of urine.

What is the mechanism of increased calcium in urine?

1. Increased intestinal absorption.
2. A lake of renal tubular reabsorption.
3. Resorption or loss of calcium from the bones.
4. Or a combination of the above mechanisms.
5. Calcium is present in urine as CaCl2, CaSO4, and CaPO4 salts.
6. Urinary calcium does not have much value in the differential diagnosis of diseases.

What are the causes of increased urine calcium?

1. Hyperparathyroidism in 30 to 80% of the cases.
2. Paget’s disease.
3. Renal tubular acidosis.
4. Vitamin D intoxication.
5. Fanconi’s syndrome.
6. Idiopathic hypercalciuria.
7. Osteoporosis.
8. Osteitis deforms.
9. Sarcoidosis.
10. Bone metastasis in osteolytic type.
11. Multiple myeloma.
12. Thyrotoxicosis.

What are the causes of decreased urinary calcium?

1. Hypoparathyroidism.
2. Vitamin D deficiency.
3. Metastatic carcinoma of the prostate.
4. Preeclampsia.
5. Malabsorption syndrome:
   1. Celiac disease.
   2. Steatorrhea.
   3. Sprue disease.
6. Renal osteodystrophy.
7. Renal failure, acute nephrosis, and nephritis.
8. Vitamin-D resistant Rickets.

Chloride in the urine:

How will you interpret chloride in the urine?

1. Chloride is most often associated with sodium balance and fluid changes.
2. Mostly, urinary excretion of chloride is parallel to the dietary intake.
3. This also reduces dietary salt intake, especially in patients with cardiovascular, hypertension, kidney, and liver diseases.

What are the indications for chloride in the urine?

1. It is advised in electrolyte imbalance.
2. In the case of dehydration.
3. In metabolic alkalosis.
4. No preservative is needed to collect the urine; only refrigerate the samples.

What is the normal chloride in urine?

1. Children’s values are much lower than adult values.
2. The values vary with the salt intake and perspiration.
3. The values vary from different lab values.
   

   Age	Value in 24 hours of urine
   Child <6 years	15 to 40 meq/day (15 to 40 mmol/day)
   Children 10 to 14 years	64 to 176 meq/day (64 to 176 mmol/day
   Adult	140 to 250 meq/day (140 to 250 mmol/day)

Magnesium in the urine:

How will you interpret magnesium in the urine?

1. Magnesium excretion through the urine controls the blood magnesium level.
2. Urinary excretion of magnesium is dependent upon dietary intake.
3. If somebody takes 200 to 500 mg/day, urinary excretion of magnesium is 75 to 150 mg/24 hours (3 to 6 mmol/day).

What are the indications for magnesium in the urine?

1. It is advised in magnesium metabolism.
2. Electrolytes balance.
3. Advised in nephrolithiasis.
4. For the 24-hour urine sample, 20 mL of 6N HCL in a metal-free container is needed. The sample should also be refrigerated.

What is the normal magnesium in urine?

1.  Urine = 75 to 150 mg/24 hours
2. urine = 3.0 to 6.0 meq/24 hours (3.0 to 6.0 mmol/day)
3. 2 to 12 meq/L

What are the causes of increased urine magnesium?

1. Chronic glomerulonephritis.
2. Increased level of blood alcohol.
3. Bartter’s syndrome.

What are the causes of decreased urine magnesium?

1. Magnesium deficiency.
2. Malabsorption.
3. Chronic renal diseases.
4. Hypoparathyroidism.
5. Hypercalciuria. It is seen in long-term parenteral therapy.
6. Decreased renal function like Addison’s disease.

Amino acids in the urine:

How will you interpret amino acids in the urine?

1. Free amino acids are found in the urine and acid filtrate of the protein-containing fluids.
2. This test is advised when there are suspected genetic abnormalities, patients with mental retardation, reduced growth, or unexplained symptoms.

What are the indications for an amino acid in urine?

1. This is advised for the screening of the inborn error of metabolism.
2. Advised for genetic abnormalities.
3. No preservative is needed to collect the 24 hours of urine; only refrigerate while collecting the samples.

What are the normal amino acids in urine?

1. Negative.

Urine analysis summary

The details are seen in part 1, complete urine analysis.

Questions and answers: