Visible Abnormalities of the Urine.—While the average amount of urine passed by a healthy adult in 24 hours is 50 ounces (three pints), there are constant variations from this rule, de pending on the amount of water ingested and the amount lost through the skin and bowels; so also do the amount of solids vary with the diet and amount of exertion. White cloudiness of the urine may be caused by the presence of pus, phosphates, mucus or bacterial growths. Reddish or qarick-dust" deposit is caused by an excess of urates, a condition ordinarily of no importance and never an indication of kidney disease. There is apt to be a diminution of the amount of urine in nephritis and a great in crease in diabetes.
Albumen in the urine is the serum albumen of the blood. In health the kidneys may allow, the passage of faint traces of this substance, but the presence of amounts large enough to be discovered by the "heat and nitric acid° test usually indicates some abnormality of the epi thelium of the tubules — congestion of these organs, inflammation of the ureter, !Adder or urethra, or an admixture of blood with the urine. Albumen may appear in the urine after severe exertion without apparent congestion of the kidneys. Certain individuals go on for years showing albumen in the urine at certain times of the day and never develop any further evi dence of Bright's disease. In some persons certain articles of food, particularly those rich in albumen, cause a temporary albuminuria. Although these forms are called ufunctional,” there is always a possibility that they may indi cate some slight kidney impairment and it is the custom of the insurance companies to re fuse applicants with albuminous urine.
Urinary casts are tiny cylinders or plugs formed in the uriniferous tubules under abnor mal conditions. They are formed of coagulated albumen, blood and epithelial cells, granular matter the result of epithelial cell degeneration, and so-called waxy matter. The clear "hyaline casts° may sometimes be found in small num bers in the urine from normal kidneys, but the constant presence of casts indicates a disease of the kidneys. These bodies are entirely invisible to the naked eye.
Uraemia.—This term denotes a group of symptoms that may appear in the course of diseases of the kidneys and during pregnancy. (See PuERPERAL ECLAMPSTA). Some toxic sub stance is held in the blood and causes one or more such symptoms, which may not be characteristic of urwmia hut to which, because of the general complex of symptoms and the known condition of the urine, the term ummic is applied. The various symptoms which it is customary to include in the category are head ache and sleeplessness, hemiplegia and aphasia, general convulsions and spasms of groups of muscles, blindness, delirium and coma, vomit ing, dyspncea and increased arterial tension.
This last condition is due to spasm of the smaller arteries and to hypertrophy of the heart.
Diseases of the Kidneys.—Acute con gestion may result from sudden obstruction of the veins, certain irritant poisons, exposure to cold, severe surgical operations, overexertion or from the infectious diseases. Besides the changes seen in the urine, albuminuria and casts, if the congestion be severe there may be fever, abdominal pain, nausea and vomiting and par tial or complete suppression of urine. The treatment consists in the removal of tilt cause and the relief of congestion by the hot pack over the lower half of the body. In its severe forms the conditions may be fatal.
Chronic Congestion.— This condition re sults from obstruction to the venous outflow, as seen in disease of the lungs, heart and liver and from the pressure of tumors: it leads to actual change of structure.
Acute Nephritis, Acute Bright's Disease.— This is an inflammation of the vital part of the kidney structure, the secreting membrane of the uriniferous tubules and of the structures around them. In such an inflammation there is congestion of the whole organ, degeneration of the epithelial lining of the tubes, exudation of serum from the blood-vessels into the tubes and consequent disturbance of the function of the organ. The most common causes of this condition are exposure to cold and wet, the poisons of scarlet fever, pregnancy, etc., certain causes being undiscoverable. The condition may also be due to other infectious diseases, to the ingestion of poisons, or to the presence of large burns of the body surface.
Some cases are so mild that the kidneys are not suspected, the patient having a slight fever, headache, loss of appetite and general malaise. The ordinary cases show considerable diminution of urine, which is loaded with al bumen and casts; there is considerable fever; nausea and vomiting are usual; and these are accompanied by more or less of dropsy, head ache and other manifestations referred to under the name of uraemia, and by a rapidly developing waxy pallor. These various symp toms are not constant, but the picture is suffi cient when the condition of the urine is investi gated. As a rule, when this condition lasts only a few weeks these cases recover com pletely and the kidneys are as good as before, but the cases of longer duration and of great severity may be fatal, or, may leave permanent changes in the organ. This last effect is par ticularly liable to follow when nephritis begins late in the course of scarlet fever, because of the permanent changes of structure induced by some particular poison generated at that time.