CHAPTER XXII 



URINE: GENERAL CHARACTERISTICS OF NORMAL AND 

 PATHOLOGICAL URINE 



Volume. The volume of urine excreted by normal individuals 

 during any definite period fluctuates within very wide limits. The 

 average output for twenty-four hours is placed by German writers 

 between 1500 and 2000 c.c. This value is not strictly applicable to con- 

 ditions in America, however, since it has been found that the average 

 normal excretion of the adult male American falls within the lower 

 values of 1000-1200 c.c. The volume-excretion is influenced greatly 

 by the diet, particularly by the ingestion of fluids. 



Certain pathological conditions cause the output of urine for any 

 definite period to depart very decidedly from the normal output. 

 Among the pathological conditions in which the volume of urine is in- 

 creased above normal are the following: Diabetes mellitus, diabetes 

 insipidus, certain diseases of the nervous system, contracted kidney, 

 amyloid degeneration of the kidney, and in convalescence from acute 

 diseases in general. Many drugs such as calomel, digitalis, acetates, 

 and salicylates also increase the volume of the urine excreted. A 

 decrease from the normal is observed in the following pathological 

 conditions: Acute nephritis, diseases of the heart and lungs, fevers, 

 diarrhcea, and vomiting. 



Color. Normal urine ordinarily possesses a yellow tint, the depth 

 of the color being dependent in part upon the density of the fluid. The 

 color of normal urine is due principally to a pigment called urochrome; 1 

 traces of hematoporphyrin, urobilin, and uroerythrin have also been 

 detected. Under pathological conditions the urine is subject to pro- 

 nounced variations in color and may contain many varieties of pig- 

 ments. Under such circumstances the urine may vary in color from an 

 extremely light yellow to a very dark brown or black. Vogel has con- 

 structed a color chart which is of some value for purposes of comparison. 

 The nature and origin of the chief variations in the urinary color are set 

 forth in tabular form by Halliburton as follows: 



1 Urochrome is believed to be identical with the yellow pigment (lactochrome) of milk 

 whey (Palmer and Coolidge: Jour. BioL Chem., 17, 251, 1914). 



376 



