What Is Protein in the Urine (Proteinuria)?
The kidneys function to remove waste and excess water and salts from the blood. Small groups of blood vessels called glomeruli filter the blood, removing these waste products and preventing proteins and other substances from being removed from the blood. If the glomeruli are damaged, protein from the blood can leak into the urine, resulting in high protein levels in the urine (called proteinuria).
Less than 150 milligrams (about 3% of a teaspoon) of protein in the urine per day is normal. More than 150 milligrams of protein in the urine per day is considered proteinuria.
What Are Symptoms of Protein in the Urine (Proteinuria)?
Protein in the urine (proteinuria) is itself a symptom of another condition and there may be no signs. When signs of protein in the urine do occur, they may include:
What Causes Protein in the Urine (Proteinuria)?
There are three types of proteinuria:
- Transient (intermittent/temporary)
- Orthostatic (related to sitting/standing or lying down)
- Loss of protein in the urine occurs while in an upright position but not when lying down
- Cause is unknown
- Persistent (always present)
- Occurs in people with underlying medical conditions, such as:
- Diseases that can affect the kidneys
- Diseases that cause the body to overproduce certain types of protein
Risk factors for developing protein in the urine include:
How Is Protein in the Urine (Proteinuria) Diagnosed?
Protein in the urine (proteinuria) is diagnosed with:
What Is the Treatment for Protein in the Urine (Proteinuria)?
There is no treatment needed for transient and orthostatic proteinuria as they are not considered harmful conditions.
Treatment for persistent protein in the urine (proteinuria) involves treating the underlying condition, and may include: