Protein in urine (proteinuria)
Protein in the urine, also called proteinuria, is often a sign of kidney problems, or an overproduction of proteins by the body.
Healthy kidneys only pass a small amount of protein through their filters.
There may be no symptoms of protein in the urine until it is picked up during medical tests. However, in some cases a person's urine may seem frothy.
Risk factors for proteinuria
The two most common risk factors for proteinuria are:
Both diabetes and high blood pressure can cause damage to the kidneys, which leads to proteinuria.
Other types of kidney disease unrelated to diabetes or high blood pressure can also cause protein to leak into the urine. Examples of other causes of proteinuria include:
- Immune system disorders
Increased production of proteins in the body can lead to proteinuria. Examples include multiple myeloma and amyloidosis.
Other risk factors for kidney disease and proteinuria include:
- Age - over 65
- Family history of kidney disease
- Race and ethnicity: African-Caribbean and Asian people are more likely than Caucasians to develop kidney disease and proteinuria.
Some people get more protein in their urine while standing than while lying down. That is known as orthostatic proteinuria.
Treatment of proteinuria
Proteinuria is not a specific disease. So its treatment depends on identifying and managing its underlying cause. If that cause is kidney disease, appropriate medical management is essential.
Untreated chronic kidney disease can lead to kidney failure.
In mild or temporary proteinuria, no treatment may be necessary.
Medication is sometimes prescribed, especially in people with diabetes and/or high blood pressure and may include two classes of medication:
- ACE inhibitors (angiotensin-converting enzyme inhibitors)
- ARBs (angiotensin receptor blockers)
Correct treatment, especially in patients with chronic disease such as diabetes and high blood pressure, is essential to prevent the progressive kidney damage that is causing the proteinuria.