CHAPTER III. 



DISEASES OF THE KIDNEYS, 

 CONGESTION OF THE KIDNEYS. 



Congestion of the kidneys is not a morbid condition in the strict 

 sense of the term, for it is merely the forerunner of nephritis caused by 

 infectious diseases or intoxications (primary active congestions) or the 

 final consequence of other diseases, such as diseases of the heart or 

 liver, mechanical compression of the vena cava or renal veins (secon- 

 dary passive congestion, cardiac kidney). 



Nevertheless, under certain circumstances the development of ne- 

 phritis may be arrested at the primary congestive stage, and it is only 

 then that an opportunity occurs of studying it as a definite complaint. 



Causation. All infections accompanied by lesions of the kidneys, 

 and these are numerous (gangrenous coryza, anthrax, parasitic haemo- 

 globinuria), produce congestion of the kidneys. 



Cold also acts directly under certain conditions, as do large doses of 

 diuretics, irritant foods the principles of which are eliminated through 

 the urine (fermenting or putrid sugar-pulp, for example), and foods rich 

 in resins, essential oils, various glucosides, tannin, etc. (young shoots of 

 trees during the spring-time). 



Symptoms. The symptoms are difficult to define accurately, and the 

 diagnosis can only be arrived at with the aid of the history. 



Eenal congestion produces pain, indicated by dull colic and repeated 

 and ineffectual attempts to urinate, suggesting acute cystitis. The 

 patients lose appetite, and present all the general symptoms of marked 

 visceral inflammation, viz., fever, acceleration of breathing, somewhat 

 tumultuous action of the heart, etc. 



External or internal examination of the kidneys reveals abnormal 

 sensitiveness. The urine is of a dark or bright-red tint, owing to the 

 presence of red blood corpuscles. These blood corpuscles are precipi- 

 tated on placing the fluid in a tall glass, and can be detected, together 

 with renal epithelium, by microscopic examination. 



The diagnosis is somewhat difficult, and it requires very careful 

 attention to distinguish between congestion of the kidney and true 

 nephritis. 



