this test give result about protein escaping into the urine and to  detect kidney damage
Sample
24-hour urin sample
methodes of protien measuring
protien is not normally found in the urine, and urine protein tests  measure protein being excreted in the urine. There are several different  kinds of urine protein tests.
1- A semi-quantitative protein  may be performed as part of aurine  analysis, generally on arondom urin sample. 
2-The quantity of protein in a 24-hour urin sample will be measured and  reported as the amount of protein excreted per 24 hours. Also, the  amount of protein in a random urine sample may be measured along with  creatinine and reported as the ratio of urine protein to creatinine .
Creatinine, a byproduct of muscle metabolism, is normally excreted into  the urine at a constant rate. When both a urine creatinine and a random  urine protein test are performed, the resulting protein/creatinine ratio  approaches the accuracy of the 24-hour urine protein test. Since saving  all of the urine for a 24-hour period can be cumbersome for adults and  difficult for infants and children, a random urine protein to creatinine  ratio is sometimes substituted for a 24-hour urine protein sample
The presence of albumin in the urine
Albuminuria
has been shown to be a sensitive indicator of kidney diseas in patients  with diabetes and with hypertension. Therefore, in some situations the  doctor may test specifically for albumin in the urine, as opposed to  total urine protein 
increasing amounts of protein over time indicate increasing damage and  decreasing kidney function.
protienuria is associated with many diseases
Amyloidosis, Bladder cancer, Drug therapies that are potentially toxic  to the kidneys, Glomerulonephriti, Goodpasture’s syndrome and Kidney  infection.