| Parameter | Expected Normal | Result and differential diagnosis | False Positive/
False increase |
False Negative/ False Decrease |
| Colour | Yellow Straw-yellow |
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| pH
Range (4.5-8.0) |
5.5 – 6.5 | Alkali: - Diet (Vegetarian, low carbohydrate diet, lots of citrus fruit) - Systemic alkalosis (metabolic or respiratory) - RTA I, Fanconi, UTI (most) - Salicylate OD, antibiotics, acetazolomideAcid: - Diet (high protein, cranberries) - Systemic acidosis - DM, DKA, starvation, COPD, diarrhoea, malabsorption - Phenylketonuria, renal TB, alkaptonuria |
Stale sample left standing (ammoniacal) | |
| Specific Gravity (g/mL) | 1.002 – 1.030 | <1.005 – DI, ATN, PN, Acute GN
1.010 – CRF, chronic GN >1.030 – Ddehydration, SIADH, adrenal insufficiency |
Alkaline urine | - Proteinuria - Glucosuria - IV contrast - Colloid |
| Protein | Negative to trace | Renal: Increased renal tubular secretion, increased glomerular filtration (glomerular disease), nephrotic syndrome, pyelonephritis, glomerulonephritis, malignant hypertension
CVS: Benign HT, CCF, SBE Other: Pre-eclampsia, gout, orthostatic proteinuria, increased plasma protein (myeloma), electric current injury, K+ depletion, Cushing’s syndrome Drugs: Aminoglycosides, gold, amphotericin, NSAID, sulphonamides, penicillins |
Concentrated urine (UO<2.5L/day)
Alkaline urine (pH >7.5) Trace residue of bleach Aceazolomide, cephalosporins, NaHCO3 |
Dilute urine (UO >5.0 litres/day)
Acidic urine (pH <5) Bence Jones globulin associated with multiple myeloma, lymphoma and macroglobulinaemia is NOT detected by dipstick urinalysis |
| Leucocytes
<15, 15, 75, 125, 500 (leu/μL ) or -, +, ++, +++ |
Negative | Pyuria | Contaminated specime
Ttrichomonas vaginalis, Drugs or foods that colour the urine red |
Intercurrent antibiotic therapy (e.g. gentamicin, tetracycline and cephalosporins)
Gglycosuria Proteinuria, High specific gravity. Low bacteria count UTI (especially in women) |
| Nitrite | Negative | Bacterial urinary infection (usually associated with Gram-negative bacteria) | Drugs or foods that colour the urine red. | Ascorbic acid
Certain bacteria such as S. saprophyticus, acinetobacter and most enterococci |
| Blood | Negative | Haematuria: trauma, infection, inflammation, infarction, calculi, neoplasia, clotting disorders or chronic infection.
Haemaglobinuria (intravascular haemolysis) Myoglobinuria (crush injury, electrocution, rhabdomyolysis) |
Hypochlorite bleach | |
| Ketones
<5, 5, 15, 50, 150 mg/dL or -, +, ++ |
Negative | Ketonuria is associated with low carbohydrate (high fat/protein) diets, starvation, diabetes, alcoholism, eclampsia and hyperthyroidism.
Overdose of insulin, isoniazid and isopropyl alcohol |
Heavily pigmented urine. Captopril, L-dopa, salicylates, phenothiazines | Underestimate the presence of ketonaemia (beta-hydroxybutyric acid can not be assessed on dipstick) |
| Bilirubin | Negative | Raised conjugated bilirubinaemia (with bilirubinuria) is associated with hepatocellular disease, cirrhosis, viral and drug induced hepatitis, biliary tract obstruction (e.g. choledocholithiasis), pancreatic causes of obstructive jaundice (e.g. carcinoma of the head of the pancreas) and recurrent idiopathic jaundice of pregnancy
Inherited condition: Dubin-Johnsons syndrome, Rotor’s syndrome |
Phenothiazines | Ascorbic acid (vitamin C)
Aged sample (conjugated bilirubin hydrolses to unconjugated bilirubin at room temperature) Rifampicin Exposure to UV light (converts bilrubin to biliverdin) |
| Urobilinogen
mg/dL |
0.2-1.0 mg/dL
<17micromol/L |
Increased: cirrhosis, infective hepatitis, extravascular haemolysis, haemolytic anaemia, pernicious anaemia, malaria, and hepatitis secondary to infectious mononucleosis
Decreased: or absent in obstructive jaundice and elevated levels of bilirubinuria |
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| Glucose | Negative | Hyperglycaemia associated with diabetes, cystinosis, Cushings syndrome or thyrotoxicosis. Liver disease (e.g. Wilsons disease)
Renal: Reduced ‘renal threshold’, renal tubular disease and pregnancy Drugs: cephalosporins, penicillins, nitrofurantoin, methyldopa, tetracycline, lithium, carbemazepine, phenothiazines, steroids and thiazides |
Hydrogen peroxide or bleach | Ascorbic acid (vitamin C) or fruit juice. Some dipsticks are affected by increased specific gravity and ketonuria |
About Mike Cadogan
