Urine test is very important in the treatment of kidney diseases. Clinically, changes in urine should be carefully observed, which includes volume, color and odour.
Ⅰ. Observations of urine colors
The normal urine color is faint yellow or deep yellow, which mainly originates from urochrome, a substance that is combined by urobilin and a type of polypeptide. Apart from urine volume, urine color is also related to weather and diet. In general, urine color is clear on cold days and yellow on hot days. If relatively acidic food is digested, urine color is deep; if relatively alkaline food is digested, urine color is more likely to be light. As for the urine color of kidney disease patients, it changes on different degrees for most kidney disease patients, depending on the kidney diseases the patients have, which includes the following scenarios.
1. Nearly colorless urine
If the urine color is light or nearly colorless, it is normally a sign of diabetes insipidus or Diabetic Nephropathy unless such risk factor as drinking too much water is expelled.
2. Yellow urine
If urine color is yellow caused by fever, not drinking enough water, vomiting or diarrhea, it is a symptom of kidney diseases such as nephrotic syndrome, chronic nephritis, allergic purpura nephritis,and renal anemia.
3. Brown, brownish black urine
Based on the generation process of urine and its contents, some neurologists argue that brown, or brownish black urine is a symptom of kidney stone, kidney failure, rapidly progressive glomerulonephritis, lupus kidney, and uremia.
4. Red urine
Some medications can cause red urine. Other than that, some kidney diseases like acute or chronic renal failure, nephrotic syndrome, uremia, lupus kidney can make red urine happen.
5. Yellowish-brown, yellow green, palm green urine
Clinically, urine with such colors rarely occurs, which is often caused by hidden nephritis, chronic renal failure, hydronephrosis, tuberculosis of kidney and pyelonephritis disease.
6. Other than the aforementioned situations, there is blue or milky urine clinically, which is led to by pathological changes in kidney as well.
Ⅱ. Urine volume
Normally, every person has approximately 1600 milliliters of urine each day. When the kidney is damaged, Glomerular filtration function will decrease, resulting to abnormal urine volume.
1. Oliguria or anuria
Oliguria means that 24-hour urine volume is below 400 milimeters. For children, the criterion is 0.8 milimeter/ per hour·kilogram . Anuria means that 24-hour urine volume is below 50 to 100 milimeters. Oliguria or anuria is mainly caused by acute renal failure that is resulted from various reasons.
Diuresis is defined as having more than 3000ml urine in 24 hours, which often occurs in nephrogenic diabetes insipidus unless such risk factor as drinking too much water is expelled.
3. Increasing volume of urine in the night
It means that the total volume of urine from 6.pm to 6.am of the next morning is more than that in the daytime, which often occurs in patients of Chronic kidney damage.
Ⅲ. Other common changes
Increasing foam in urine means that there is more Solute components in urine, for example, proteinuria . If urine smells like ammonia, it normally means urinary infection happens. Aromatic fruit flavor in urine is a symptom of diabetic ketoacidosis.