Lupus nephritis is a kidney condition that causes symptoms like foamy urine, blood in the urine, and swelling of the legs, hands, or face. It’s caused by the autoimmune disease systemic lupus erythematosus (SLE), which is the most common type of lupus and often simply called lupus.
Lupus occurs when a person’s immune system attacks their body and its tissues, which can lead to kidney damage or, in severe cases, kidney failure. Kidney damage affects important kidney function, including filtering waste and excess fluid out of the blood and into the urine.
During lupus nephritis, groups of small blood vessels in the kidney — known as glomeruli — become damaged by the immune system. The glomeruli filter waste out of the blood, and that waste ends up in the urine. Many symptoms of lupus nephritis are associated with damage to the kidney and the glomeruli. Lupus nephritis symptoms generally coincide with other lupus symptoms, such as fatigue, joint pain, and stiffness.
The urine can appear foamy in people with lupus nephritis, due to excess protein. This condition is known as proteinuria. The damage that occurs to the glomeruli during lupus nephritis can allow protein from the blood to leak into the urine.
When the urine is a light brown or pink color, it may contain blood. This condition is referred to as hematuria. Blood can leak into the urine when the glomeruli are damaged.
Besides removing waste from the blood, kidneys also remove excess fluid from the body. When the kidneys are damaged, fluid can accumulate in places such as the legs, ankles, hands, and face. Swelling can also appear around the eyes. This accumulation of excess fluid is commonly referred to as edema.
People with lupus nephritis may gain weight because they’re retaining fluid. Weight gain is associated with lupus in general and can be a side effect of medications, particularly corticosteroids.
Additionally, symptoms of lupus such as joint pain or fatigue can interfere with a person’s ability to eat healthy and maintain physical activity, leading to a more sedentary lifestyle. Health experts warn that physical inactivity can lead to other types of disability, as well as premature death.
Frequent urination, especially during the night, is another common symptom of lupus nephritis. It can serve as an indication that the kidneys are not working properly. When fluid builds up due to kidney dysfunction in lupus nephritis, the body will expel more urine as a result. People with lupus nephritis also have a greater risk of urinary tract infections (UTIs), which can increase the urge to urinate more frequently.
Up to 50 percent of people living with lupus develop lupus nephritis. Your doctor should monitor you for signs of the condition. They’ll run tests on the urine and blood, and they may even want a biopsy of the kidney tissue. The results of these tests may indicate the presence of lupus nephritis.
If a doctor detects high levels of creatinine in the blood of someone living with lupus, it could indicate lupus nephritis. Creatinine is a natural waste product created by the breakdown of muscles in the body. Properly functioning kidneys should filter this waste out of the blood and into the urine.
The kidneys play a role in controlling blood pressure. Kidney damage resulting from lupus nephritis can affect the organ’s ability to regulate blood pressure, leading to hypertension (high blood pressure).
If a doctor suspects you have lupus nephritis, they may want to perform a kidney biopsy. This procedure involves taking a very small piece of tissue from the kidney and examining it under a microscope. A kidney biopsy is performed under light sedation or general anesthesia, often in a hospital or outpatient center.
There are six stages or classes of lupus nephritis. As the disease worsens, the stages progress. A doctor can identify lupus nephritis stages based on a kidney biopsy and a person’s kidney function.
Some people living with lupus nephritis will progress to chronic kidney disease (CKD). If more damage occurs and kidney function gets worse, some people may progress from CKD to end-stage renal disease (ESRD), also called kidney failure. Up to 30 percent of people with lupus nephritis will develop ESRD. People with ESRD generally require dialysis or a kidney transplant.
The following symptoms or signs of CKD and ESRD may indicate a person’s kidney function is getting worse:
A doctor may also be able to tell that lupus nephritis is getting worse by running blood and urine tests and performing a kidney biopsy.
Fortunately, treatments for lupus and lupus nephritis can slow the disease’s progression and limit damage to the kidneys. Taking certain medications, along with living a healthy lifestyle that supports the kidneys, can benefit many people living with lupus nephritis.
You should talk to your doctor if you are experiencing any of the signs and symptoms of lupus nephritis, CKD, or ESRD. You should also talk to your doctor if you notice your symptoms of lupus nephritis getting worse, which could indicate the disease is progressing. You may require changes to your treatment plan or a different kind of therapy, such as dialysis.
People with lupus nephritis are at higher risk for heart and blood vessel problems. Heart failure is a major complication of kidney disease, as are other conditions associated with the heart. If you suspect you are experiencing the symptoms of a heart attack — including chest pain and shortness of breath — get emergency help right away.
MyLupusTeam is the social network for people with lupus and their loved ones. On MyLupusTeam, more than 218,000 members come together to ask questions, give advice, and share their stories with others who understand life with lupus. On MyLupusTeam, you can chat with more than 14,000 members who have lupus nephritis.
Are you living with lupus nephritis? What symptoms have you had with lupus nephritis? Share your experience in the comments below, or start a conversation by posting on your Activities page.