Albumin in Urine

Albumin is a protein that is found in blood. It is a healthy protein, which travels in bloodstream. When your kidneys filter the blood and separate wastes from other healthy substances in the blood, albumin is retained and does not cross the filters or glomerulus. This means that in normal circumstances, healthy persons should not have albumin in urine. However, if the kidneys are impaired, then the albumin substance is passed out together with waste products meaning that it ends up in the urine. 

A damaged kidney allows some albumin molecules to pass through the glomerulus and wind up in the urine. The less albumin in urine the better, because it may indicate that your kidneys may not have problems. Persons who are at risk of suffering kidney disease may be checked of their albumin levels in blood together with the glomerular filtration rate- GFR. The amount of this protein in urine may be described in different terms such as microalbuminuria, macroalbuminuria, urine protein, proteinuria, urine creatinine ratio, and albuminuria. 

When is urine albumin test done?

If the urine albumin result is below 30 milligrams per day, this may be regarded as normal but when it is above this figure, it may indicate a kidney disease. Albumin test is performed when your doctor suspects that you may be suffering from a kidney disease. It is a method used as a screening test for kidney damage. 

Usually, protein is not released to the urine. When a routine dipstick test is done, a person without kidney disease may not show protein in urine. However, there are times when very tiny amounts of proteins may be detected in urine with use of specialized test techniques. The presence of small tiny amounts of protein found in urine may not necessarily indicate an illness. 

Although the kidney is supposed to retain large substance such as albumin proteins in the bloodstream, at times, very tiny molecules of albumin can pass the filtration process and join the urine substance. However, those small amounts of proteins are able to get through the body and reabsorbed back to the bloodstream. 

When the levels of protein in blood is too high, some proteins may pass the kidney filtering process and appear in urine even when the kidney are working properly. On the other hand, when the kidney is damaged or diseased, protein molecules will pass and appear on urine even in situations where the protein levels are normal. 

Urine albumin test

Urine protein or albumin in urine test may be done using a random sample of your urine as well as a dipstick test. What this means is that urinary albumin test may be done with a qualitative method such as simple dipstick, which shows a change in color thus signifying the presence of albumin. The test may also be conducted through a 24-hour urine protein test. This is a quantitative method that is used to collect urine in 24 hours and analyze the samples of albumin levels. 

In the random urine sample, the normal values may be around 0 to 8 milligram per deciliter. In the 24-hour urine sample test, the urine collection is done in a large container after the morning urination. Another subsequent collection is done in the next 24 hours including the morning sample during the second day. 

Usually, the urine is kept in a tight-fitting capped container and under a refrigerator. For the 24-hour urine sample collection, the test results may show normal values between 50 and 80 milligrams per 24 hours. These test results may also vary from one laboratory to another and some laboratories may use different measures or do a test on different samples. 

The results of urine protein test may be affected by factors such as drugs. It is important to inform your doctor about any medications you may be taking. Other aspects that may affect the results are such as dehydration, severe emotional stress, urinary tract infection, strenuous exercise, and urine contamination by fluid from vagina. In addition, the results may be misleading if you have had a radiology scan within the past three days prior to the urine test. 

The meaning of the urine protein test

When the test shows small increases in albumin levels in urine, this may not be a cause for concern since it can happen where tiny amounts of the proteins end up in the urine. However, these are reabsorbed back to the body. When there is presence of large amounts of albumin in urine, it may be as a result of conditions like amyloidosis, congestive heart failure, bladder tumor, diabetic nephropathy, glomerulonephritis, dehydration, and heavy metal poisoning. 

Large amounts of albumin in urine may also be caused by drugs that damage the kidney such as nephrotoxic drugs. Urinary tract infection, preeclampsia, systemic lupus erythematosus, goodpasture syndrome, and polycystic kidney disease may be other causes for the increased levels of albumin in urine.