What is albumin in urine?
Albumin is a protein that is produced by the liver and makes up a large part of our proteins in the blood. Normally only small amounts of the protein are excreted in the urine. Elevated levels of the protein albumin in urine can indicate a kidney problem. This is known as albuminuria.
What are the standard values?
The standard value for albumin, which is physiologically excreted in the urine, is a maximum of 20mg for urine left spontaneously in the morning. If the albumin value is determined in a 24-hour urine collection, the standard value is a maximum of 30mg. In a 24-hour urine collection urine, the urine is collected over 24 hours and the albumin content is then determined. Not every deviation from the standard value is pathological. The albumin content in urine can be increased, for example, after heavy physical exertion or during pregnancy.
What are the causes of albumin in urine?
The most common causes of albumin in urine can be: Physiological (excretion up to 30mg/day) Heavy physical strain Pregnancy (normal value up to 300mg/day) Kidney diseases (e.g. kidney weakness or inflammation of the kidneys) Inflammation High blood pressure Diabetes in children: nephrotic syndrome This is a list of the most common causes of (elevated) albumin levels in urine. There are also many other causes of (elevated) urinary albumin levels. – Physiological (excretion up to 30mg/day)
- Heavy physical strain
- Pregnancy (standard value up to 300mg/day)
- Kidney diseases (e.g. kidney weakness or inflammation of the kidneys)
- High blood pressure
- In children: nephrotic syndrome
Diabetic nephropathy is a secondary disease that can occur in the context of diabetes mellitus. Increased albumin levels in the urine indicate the beginning of kidney damage. In people who suffer from diabetes mellitus, the albumin value in the urine is regularly determined in order to detect kidney damage at an early stage and to slow down the progression of the disease through targeted therapy. It is important that the “sugar” is well adjusted so that such secondary diseases do not occur or occur as late as possible.
How is albumin in urine diagnosed?
To determine the albumin level in urine, the doctor needs either a sample of the urine left spontaneously in the morning or a 24-hour urine collection kit. The urine is collected for one day and a sample is then taken by the doctor. The urine sample is then analysed in the laboratory.
There are special laboratory tests that can detect the various proteins, such as albumin. In order to be able to confirm the diagnosis of elevated albumin levels in the urine, two urine samples are examined at an adequate interval of a few weeks, as the albumin level can also be physiologically elevated at times, such as after heavy physical exercise. With a conventional urine test strip it can usually be detected whether increased protein levels are present in the urine.
However, no statement can be made as to whether the detected proteins in the urine are albumin and in what quantity it is present in the urine. Test strips are often not sensitive enough to detect small amounts of albumin or proteins in urine, so that more specific measuring methods have to be used. A test strip cannot therefore be used to make a statement about possible kidney disease. If kidney disease is suspected, a differential diagnosis should always be carried out by a doctor.