Color of Urine.

 

Color of Urine

PKGhatak, MD

The normal color of urine is pale yellow. The hemoglobin breakdown product bilirubin is excreted by the liver in the bile. Most of the bilirubin is eliminated from the body in the stool, some 20 % is reabsorbed and filtered by the kidneys. In the urine it appears an urobilirubin and that colors the urine.

..Dehydration produces dark yellow color urine; pale urine is produced from drinking several glasses of beer. Urine color becomes barely noticeable or absent in common bile duct obstruction from impacted gall stones or pancreatic cancer.

..Consuming beetroot, carrots, and blackberries, make urine red and various shades of yellow. Green urine is likewise seen after eating asparagus. In the summer months eating ice shavings with colored syrup and colored ice cream can give a variety of colored urine.

..People taking prescription medications, if they read the printed information given by the pharmacy, will find certain pills may discolor the urine.

 Drugs producing colored urine: -

..Orange color – Rifampin and other Rifampin derivatives, Sulfadiazine, Senna. Warfarin, Phenazopyridine.

..Pink color – Phenolphthalein, Vitamin B12, Senna.

..Brown color – Nitrofurantoin, Metronidazole, chloroquine.

 .Black color – Sorbitol, Methyldopa.

..Blue color – IV methylene blue. Indigo carmine.

..Green color – Promethazine, cimetidine, Amitriptyline, Indocin, Metoclopramide.

 Diseases producing colored urine: - Red urine. - Bleeding from the urinary bladder, kidneys and urinary tract due to stones, tumors, tuberculosis and trauma including surgery.

..Brown urine. - Free hemoglobin and myoglobin (hemoglobin of skeletal muscles) in the urine. This may arise from crush injuries, Rhabdomyolysis. Prolonged march. Electric shock, Seizures. Massive pulmonary infarction and Intravascular hemolysis. Only a few important intramuscular hemolytic causes are mentioned here.

..Hemolytic anemia is classified as I. Inherited and II. Acquired.

 I. Inherited intravascular hemolysis due to 1. abnormal cell shape and size e.g. Thalassemia, Sickle cell anemia, Hereditary spherocytosis. Elliptocytosis.        2. Enzyme deficiency. G6PD (glucose 6 phosphatase deficiency) PKD (pyruvate kinase deficiency).

II Acquired hemolytic anemia. Burns. Autoantibodies –1. Immune hemolytic e.g., CLL (chronic lymphatic leukemia) Non-Hodgkin lymphoma. 2. Autoimmune hemolytic e.g., minor blood group Lupus erythematosus. 3. Autoimmune hemolytic e.g., post transfusion hemolysis, Hydrops fetalis and hemolytic anemia in newborn – Rh negative mother sensitized by Rh positive baby during pregnancy, mother's antibodies cross the placenta and hemolyze fetal RBCs of the subsequent pregnancy. 4. Drug induced antibodies e.g., Penicillin, Cephalosporins, Levofloxacin, NSADS, Methyldopa, Nitrofurantoin. 5. Mechanical causes- e.g. RBC breaks down in the microcirculation e.g., TTP (thrombotic thrombocytopenic purpura). ITTP (idiopathic thrombocytopenic purpura. Mechanical cardiac valves. 6. Miscellaneous e.g., PNH (paroxysmal nocturnal hemoglobinuria.

Hemolysis is due to the presence of antibodies. e.g., Cold agglutinins in mycoplasma pneumonia.

.. Bacterial hemolysins – cholera toxin, Clostridium perfriengence (gas gangrene, CMV, Rickettsia, Brucella, Trypanosoma, EBV (Epstein Barr virus).

 Autoimmune hemolytic anemia. Paroxysmal nocturnal hemolysis. Mediterranean fever.

..Other causes – Acute renal tubular necrosis. Acute glomerulonephritis, Good Pasture syndrome, snake bite, CO poisoning, barbiturate poisoning, polymyositis. muscular dystrophy, McArdle syndrome.

 ..Intracellular Parasites- Malaria, Babesia, Trypanosoma.

.. Black urine: Malignant melanoma.

..White urine. Lymphatic obstruction. Fungal UTI. Cellular derbies from TB.

. Snowflake urine. Calcium phosphate crystals.

. White cloud in oxalosis.

. Standing urine open to air changing to dark or black due to Alkaptonuria.

.. Spurious color changes – red diaper syndrome due to growth of bacteria Serratia marcescens.

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