Urine pH and its Significance

What urine sample is needed for urine pH?

1. The test sample is urine.
2. A fresh urine sample is preferred.

What are the indications for urine pH?

1. Urine pH tells the systemic acid-base disorder:
   1. Is it metabolic?
   2. Or Respiratory.
   3. Renal tubular acidosis.
2. pH is used to identify the type of crystals.
3. Urinary pH is very important in the treatment of renal stones and crystals.
4. pH is important in managing diseases, bacteriuria, renal calculi, and drug therapy.

How would you discuss the pathophysiology of urine pH?

1. The small changes in the urine pH are of little significance.
2. The lungs and the kidneys are the major regulators of the acid-base content in the body.
   1. The lungs and kidneys maintain the pH and acid-base balance by secreting H⁺ ions in ammonium ions, hydrogen phosphate, and weak organic acid and reabsorbing bicarbonate from the filtrate in the convoluted tubules.
3. A healthy individual will produce morning urine as acidic with a pH of 5.0  to 6.0.
   1. Alkaline urine may be found after meals (alkaline tide).
   2. The random pH ranges from 4.5 to 8.0.
4. pH measures the concentration of urine’s free hydrogen (H⁺) ions.
5. Urine pH:
   1. 7.0 = neutral
   2. < 7.0 = acidic.
   3. > 7.0 = alkaline.
6. Urine pH indicates the renal tubule’s ability:
   1. To maintain normal H⁺ concentration in the plasma.
   2. To maintain the extracellular H⁺ concentration.

What is the mechanism to control urine pH?

1. The kidneys are the major regulator of the acid-base content in the body.
2. Renal distal tubules are the most active site for homeostasis for:
   1. Plasma electrolyte balance.
   2. Plasma acid-base balance.
3. In the distal tubules, there is a combination of secretion and reabsorption of:
   1. Na⁺
   2. K ⁺
   3. H⁺
4. In the distal tubules, there is an exchange of H⁺ for Na^+.

5. Kidneys have the main function of producing alkaline or acidic urine and maintaining constant body pH.
6. Kidneys maintain acid-base by absorption of Na⁺ and excretion of H⁺ and ammonia.

What is the significance of urine pH?

1. When there is no renal dysfunction, the urine will be acidic in respiratory or metabolic acidosis.
2. In the case of respiratory or metabolic alkalosis, urine will be alkaline when there is no renal dysfunction.

Urine pH in acidosis and alkalosis

What is the Hydrogen ion secretion and reabsorption in the kidney?

What are the causes of alkaline and acidic urine??

What is the normal urine pH?

Source 2

• Normal pH varies from 4.6 to  8.0  (average 6.0).

How will you measure the urine pH?

1. Test strips were impregnated with the indicator.
   1. Methyl red in urine pH below 4.2 is red.
   2. pH above 6.2 is yellow.
2. Bromthymol blue is yellow at a pH value below 6.0.
   1. Blue at the value above 7.6.
   2. In between the pH, there are shades of orange and green.
   3. Read after 60 seconds and compare the colors with the given color chart.
   4. PH 5 is orange, and pH 8.5 is blue.

5. pH electrodes:

   1. These are more accurate.

What are the causes of high pH >7.0 in urine?

1. It Indicates Alkaline urine, maybe due to the following:
   1. Gastric suction
   2. Renal Failure
   3. Vomiting (metabolic acidosis)
   4. Respiratory alkalosis.
   5. Hyperventilation.
   6. Potassium depletion.
   7. A bacterial infection like Proteus and Pseudomonas.

What are the causes of low pH <7.0 in urine?

1. It indicates Acidic urine, maybe due to the following:
   1. Metabolic acidosis.
   2. A bacterial infection like E.coli.
   3. Renal tuberculosis.
   4. Fever.
   5. Diabetic ketosis.
   6. Diarrhea.
   7. Starvation.
   8. Uremia.

What is the role of urine pH in renal calculi?

1. The renal stone formation depends upon urine pH.
   1. Calcium phosphate, calcium carbonate, and magnesium phosphate stones form in alkaline pH,  so keep the urine acidic to prevent their formation.
   2. Uric acid, calcium oxalate, and cystine form in acidic urine; keep the urine pH alkaline to prevent its formation.

What is the role of urine pH in drug therapy?

1. Neomycin, kanamycin, and streptomycin are effective in alkaline urine.
2. Salicylate intoxication keeps the urine pH alkaline.
3. Sulfa therapy forms crystals, which can be prevented by keeping urine pH alkaline.

What is the role of urine pH in diseases?

1. Keep urine pH acidic during the following:
   1. The treatment of urinary tract infection.
   2. In persistent bacteriuria.
   3. In renal calculi, which develop in alkaline urine.

What is the effect of diet on urine pH?

1. Vegetarian diet, citrus fruits keep urine alkaline.
2. A diet rich in protein (meat) keeps urine acidic.
3. Cranberry juice keeps urine acidic, and some believe it is a remedy for UTIs.

How would you summarize the significance of the urine pH?

1. For assessment of metabolic alkalosis and acidosis.
2. For evaluation of respiratory alkalosis and acidosis.
3. To find an unsatisfactory urine specimen.
4. Urinary pH is important in the management of renal stones or crystals.
   1. Uric acid stones precipitate in acidic urine and are soluble in basic urine.
   2. Alkaline urine will precipitate calcium or calcium phosphate, and acidic urine will dissolve these stones.
5. Role in the formation of renal calculi.
6. Role of pH in the differentiation of the crystals in the urine.
7. pH is important in the treatment of urinary tract infections.
   1. Alkaline urine is needed to treat sulfonamide and streptomycin therapy and prevent their precipitation in the kidneys.
8. Alkaline pH is needed during blood transfusion and salicylate intoxication.
   1. In the case of cystitis, pH is kept acidic to fight bacterial infection and to prevent the formation of alkaline stones.
9. Role of pH in renal tubular acidosis.

What is the role of pH in various diseases?

What is the Normal picture of the urine?

Questions and answers: