Nephrology

Urine Colors

The color of urine is dependent on the state of the patient's hydration, foods eaten, dyes added to foods, disease states, and drugs. Parents often will call the pediatrician to ask questions about the change in color of the child's urine. Some of the common causes of urinary color changes will be discussed. An evaluation of the patient with urine color changes will start with a history of diet, drugs, general state of health, any vomiting or diarrhea, and a physical examination.

Red

  1. Hematuria- microscopic examination of urine will demonstrate the present of RBCs.
  2. Myoglobinuria- there will be a brownish-red color. Often associated with ischemic muscle damage, crush injuries, and after vigorous exercise.
  3. Hemoglobinuria- with intravascular hemolysis
  4. "Pink diaper syndrome"- there is a pinkish discoloration on the diaper secondary to urate crystals in the urine. This is a benign condition.
  5. Foods
    1. Berries
    2. Beets
    3. Food coloring
  6. Drugs
    1. Dilantin
    2. Phenothiazines
    3. Adriamycin
    4. Use of Deferoxamine will cause vin rose colored urine if serum Fe is elevated.
  7. Presence of Serratia marcescens in the urine. This is a non-pathogen

Orange

  1. Pyridium
  2. Rifampin
  3. Urate crystals

Green

  1. Food colorings
  2. Increased carotene in the diet
  3. Pseudomonas aeruginosa infection

Brown or Black

  1. Hemoglobin
  2. Bilirubin
  3. Flagyl
  4. Nitrofurans
  5. Alkaptonuria- on standing, the urine will turn a dark color.

Yellow

  1. Bile pigments

Blue

  1. Methylene blue
  2. A tryptophan absorption defect may lead to production of indigotin, an oxidative product

Milky or Cloudy Color

  1. Pus cells and bacteria in the urine
  2. After sitting, urine may form crystals that makes urine appear cloudy