Urine Color Analysis

• Urine color variations can provide insights into a patient's health status.

Colorless Urine

• Often linked to recent fluid consumption.
• Commonly found in random urine specimens.

Pale Yellow Urine

• May indicate polyuria or diabetes insipidus, resulting in increased 24-hour urine volume.
• Can be associated with diabetes mellitus, characterized by elevated specific gravity and a positive glucose test.
• Can be caused by dilute random specimens due to recent fluid intake.

Dark Yellow Urine

• Suggests a concentrated urine sample.
• It may occur normally after intense exercise or in the first morning specimen.

Amber Urine

• Indicates dehydration, possibly due to fever or burns.

Yellow-Green to Yellow-Brown Urine

• Caused by bilirubin oxidizing to biliverdin.
• May produce colored foam in acidic urine, potentially leading to false-negative chemical test results for bilirubin.

Orange Urine

• Indicates the presence of bilirubin, resulting in yellow foam upon shaking and a positive chemical test.
• May be due to acriflavine, which yields negative bile test results, and possible green fluorescence.
• Caused by phenazopyridine (Pyridium), which is Commonly administered for urinary tract infections, it may cause orange foam and a thick orange pigment, potentially interfering with reagent strip readings.
• May be caused by Nitrofurantoin, an antibiotic used for urinary tract infections.
• Phenindione, an anticoagulant, can cause orange urine in alkaline conditions but is colorless in acidic urine.

Green Urine

• May indicate a Pseudomonas infection, confirmed by a positive urine culture.

Blue-Green Urine

• Can be caused by amitriptyline, an antidepressant.
• Methocarbamol (Robaxin), a muscle relaxant, can result in green-brown urine.
• Can be caused by Clorets or indican, a bacterial infection (Klebsiella, Providencia).
• May be due to methylene blue or phenol when oxidized, also fistulas.

Pink to Red Urine

• Presence of RBCs: Indicates cloudy urine with positive chemical test results for blood and RBCs visible microscopically.
• Hemoglobin: Indicates clear urine with positive chemical test results for blood, indicating intravascular hemolysis.
• Myoglobin: Indicates clear urine with positive chemical test results for blood and muscle damage.
• Indicate Porphyrins: Negative chemical test results for blood. Detected with Watson-Schwartz screening test or fluorescence under ultraviolet light.
• May be from beets in alkaline urine of genetically susceptible individuals.
• Rifampin, a tuberculosis medication, can cause this coloration.
• Menstrual contamination can result, characterized by a cloudy specimen with RBCs, mucus, and clots.

Brown to Black Urine

• RBCs oxidized to methemoglobin: Seen in acidic urine after standing; positive chemical test result for blood.
• Methemoglobin: Denatured hemoglobin.
• Homogentisic acid (alkaptonuria): Seen in alkaline urine after standing; specific tests are available.
• Melanin or melanogen: Urine darkens on standing and reacts with nitroprusside and ferric chloride.
• Phenol derivatives: Interfere with copper reduction tests.
• Argyrol (antiseptic): Color disappears with ferric chloride.
• Methyldopa or levodopa: Antihypertensive.
• Metronidazole (Flagyl): Darkens on standing.