Common Urinary Crystals: Introduction, Identification Features, Normal Range and Clinical Singificance

Common Urinary Crystals Introduction, Identification Features, Normal Range and Clinical Singificance

Introductions of Common Urinary Crystals

Common Urinary Crystals in urine routine examination are completed in the following steps- First request the patient to bring a urine specimen. After the arrival of the specimen in the clinical laboratory, take nearly 5 ml of urine and centrifuge it. Put a drop of the mixed sediment part on a clean and grease-free glass slide and place a coverslip over it.  Examine the entire 22- by 22-mm coverslip systematically with the low power objective (10X ) and low light intensity. If any suspicious objects are encountered, examine with the high dry objective (40X). Normal Crystalline deposits in Urine Examination shows various forms of Crystals with the following properties-

Crystals have a regular geometric shape,

Calcium oxalate (acid urine)

Shape: like an envelope

size: about the size of 1-2 RBC

Urine acid (acid urine)

shape: varies (square, diamond-shaped, cubical or rose-shaped)

size: 30-150 µm, maybe very small size

colour yellow or brownish-red

Triple phosphates ( neutral or alkaline urine)

shape: rectangular or like a fern leaf or star

colour: colourless, refractile

Common Urinary Crystals

The common urinary crystals are calcium oxalate crystals,  urate Crystals or uric acid crystals, triple phosphate crystals, calcium carbonate crystals, cholesterol crystals, amorphous urates, and amorphous phosphate.

  • Calcium oxalate crystals: They are colorless crystals and may be found in various shapes like octahedral, envelope, oval spheres, and biconcave disks that have a dumbbell shape. They are mainly found in acidic and neutral but may also be encountered in alkaline urine. They are associated with both healthy and pathological conditions and can also be seen in urine after ingestion of spinach, tomatoes, garlic, vitamin C, etc.
  • Urate Crystals or Uric acid Crystals: Urate Crystals also called “amorphous urate crystals are found in acidic urine (pH less than 5.5). The formation can be caused by a combination of factors, including a diet rich in meat, decreased urine volume, or a condition that acidifies urine such as chronic diarrhoea. They may be found in both healthy and pathological conditions.
  • Triple Phosphate Crystals: They are ammonium magnesium phosphate and colourless prisms with 3 to 6 sides and frequently with the oblique ends. They are found in both healthy and pathological conditions. They are soluble in acetic acid.
  • Calcium Carbonate Crystals: Introduction of Carbonate Crystals or Calcium carbonate Crystals is large circular crystals with radial striations with smooth surfaces in shape. They are slightly brown in colour and found in alkaline urine, pH is greater than 6.5. They are caused by a combination of factors including decreased urine volume or a condition that alkalinizes urine, such as a vegetarian diet, chronic diarrhoea, urinary tract infections or certain medications.
  • Ammonium biurate Crystals: These crystals are yellow-brown spherical bodies with or without long, irregular spicules and they are soluble in acetic acid and dissolved by heating.
  • Cholesterol Crystals: Cholesterol Crystals are long rectangles with cut-out corners in shapes and they formed due to renal tubular disease, which can lead to renal failure if left untreated. They are found in both neutral and acid urine and are rarely detected. They’re most likely to appear after the urine sample has been re-frigerated and insoluble in acids and alkalis but soluble in ether, ethanol, and chloroform.
  • Amorphous Urates are salt of sodium, potassium, magnesium, and calcium. The actual form is non-crystalline and amorphous. Their appearance s are yellow-red granular and soluble in alkali at 60°C.
  •  Amorphous phosphates: They are in amorphous, granular form and soluble in acetic acid.

Identification Features of Common Urinary Crystals

 

Calcium oxalate crystals: They are colorless crystals and may be found in various shapes like an octahedral, envelope, and dumb-bell shapes.

Urate Crystals or Uric acid Crystals: They show diamond rhombic or rosette form.

Triple Phosphate Crystals: They ate colorless prisms with 3 to 6 sides and frequently with the oblique ends.

Calcium Carbonate Crystals: They are variably sized crystals that frequently appear as large spheroids with radial striations while smaller crystals with a round to ovoid shapes.

Ammonium biurate Crystals: They are yellow-brown spherical bodies with or without long, irregular spicules.

Cholesterol Crystals: They look like clear long rectangles with cut-out corners.

Ammonium biurate Crystals: They appear as brown or yellow-brown spherical bodies with irregular protrusions also called thorn-apples.

Amorphous Urates and Amorphous phosphates are amorphous with granular form.

 

Differences of Amorphous urate and phosphate

Amorphous Urate

  • Found in acidic urine
  • Colour of precipitate pink or brick dust
  • Insoluble in acetic acid

Amorphous phosphate

  • Found in alkaline urine
  • White in colour
  • Soluble in acidic urine

Common Urinary Crystals Clinical Significances

Calcium oxalate crystals: They are found in diabetes mellitus, liver diseases and
chronic liver diseases.

Urate Crystals or Uric acid Crystals: There is little clinical significance however they can be found in the following conditions like gout or during chemotherapy and kidney stones, acute febrile conditions, and chronic nephritis.

Calcium Carbonate Crystal: It shows little clinical significance even though conditions like decreased urine volume or a condition that alkalinizes urine, such as a vegetarian diet, chronic diarrhoea, urinary tract infections or certain medications. Increased calcium levels that are too high such as immobilization, overactive parathyroid glands and bone metastases.

Triple phosphate crystals are associated with chronic cystitis, enlarge prostate, and chronic pyelitis.

Ammonium biurate crystals are only clinically significant if they are found in fresh urine.

Cholesterol Crystals: Severe kidney disease or when a lymphatic vessel has ruptured into the renal pelvis.

Amorphous urates and amorphous phosphates have no clinical significance.

Common Urinary Crystals videos links @

 

 

[4251 visitors]

Comments

© 2026 Universe84a.com | All Rights Reserved

16664558

Visitors

Nakaseomyces glabratus-Introduction, Morphology, Pathogenicity, Lab Diagnosis, Treatment, Prevention, and Keynotes | Pichia kudriavzevii-Introduction, Morphology, Pathogenicity, Lab Diagnosis, Treatment, Prevention, and Keynotes | Klebsiella aerogenes : Introduction, Morphology, Pathogenicity, Lab Diagnosis, Treatment, Prevention, and Keynotes | Lactococcus garvieae: Introduction, Pathogenicity, Lab Diagnosis, Treatment, Prevention, and Keynotes | Dalmau Plate Culture: Introduction, Purpose and Mechanism, Procedure, and Key Morphological Identifiers | Rothia kristinae: Introduction, Pathogenicity, Lab Diagnosis, Treatment, Prevention, and Keynotes | Cord Factor: Introduction, Clinical Significance, and Keynotes