Proteinuria

Proteinuria is defined as an abnormal amount of protein in the urine. The kidneys are designed to remove toxins and fluid from the blood, but protein is not supposed to be filtered out of the blood and into the urine.  When protein is found in the urine, it typically is a sign of kidney disease.

Causes of Proteinuria

Proteinuria may occur in many different types of kidney disease.  Some diseases that are commonly associated with proteinuria include:

  • Diabetes
  • Hypertension
  • Inflammatory or autoimmune diseases
  • Multiple myeloma or amyloidosis

Symptoms of Proteinuria

Early stages of proteinuria do not often produce any symptoms, but patients with large amounts of protein may notice the following symptoms:

  • Swelling in the hands, feet, face, or abdomen
  • Urine that appears foamy

Diagnosis of Proteinuria

Albumin is the most abundant protein in the blood. Proteinuria often can be diagnosed through a simple urinalysis.  In situations where the amount of proteinuria is very low, or when unusual proteins are suspected to be present in the urine, samples can be sent to an outside lab for more sensitive testing.

Occasionally, healthcare professionals will look for proteinuria if the level of albumin is found to be low in the blood, and a cause has not been identifed.

Treatment of Proteinuria

Treatment for proteinuria requires identifying the underlying cause, and treatment is tailored to address each patient's unique situation.  Depending on the cause, treatments may include:

  • Low protein diet
  • Reducing dietary sodium intake
  • Diuretics to remove excess fluid
  • Medication for diabetes and/or high blood pressure
  • Immunosuppressive medications
  • Referral to other specialists if the problems extends to other organ systems

Additional Resources