Diagnosing Lupus Nephritis

In some people, one or more following overt symptoms may be signs of lupus nephritis:

• dark urine
• foamy, frothy urine
• getting up to urinate during the night
• swelling or puffiness in the feet, ankles and legs, worsening as the day goes on
• weight gain
• high blood pressure

However, some people have no overt symptoms of kidney disease, and so it must be diagnosed by laboratory tests. Urine tests may show blood or excess protein in the urine. Blood tests may show high levels of waste materials like creatinine and urea, indicating declining kidney function.

A kidney biopsy is often used to confirm a diagnosis of lupus nephritis and to determine how far the disease has progressed. In a biopsy, a sample of kidney tissue is taken using a long needle inserted through the skin. This tissue sample is then examined under a microscope.