What is membranous nephropathy?
Usually, the immune system helps to protect our bodies from infections. But in membranous nephropathy, and in many other kidney diseases, it is misdirected and attacks healthy kidney tissue. This damages the tiny filters of the kidney, called the glomeruli.
What causes membranous nephropathy?
Our immune system produces antibodies. These are proteins which help protect the body from harmful invaders, such as bacteria or viruses. In membranous nephropathy, antibodies mistakenly target and damage healthy glomeruli.
In some cases, the cause of membranous nephropathy is unknown, called idiopathic membranous nephropathy, but this is becoming less frequent as we discover more about the condition and understand what the antibodies are attacking. We now understand which antibodies are involved in a large proportion of cases, and for some, we can test for these antibodies in the blood.
In other cases, membranous nephropathy develops because of another underlying condition, such as:
- Infections, including hepatitis B or C
- Cancers
- Certain medications, such as non-steroidal anti-inflammatory drugs (NSAIDs) and penicillamine
- Autoimmune diseases, such as lupus
- Thyroid gland problems
Membranous nephropathy usually affects adults and is rarer in children.
What are the symptoms of membranous nephropathy?
Damage to the glomeruli means the filtering system doesn’t work well and the leaky filters let protein escape into the urine from the blood. This lowers the level of proteins in the blood and leads to swelling, a condition called nephrotic syndrome. Signs of this include:
- Frothy or bubbly urine (caused by the protein)
- Swelling, often around the eyes, tummy, feet and legs.
Some patients may notice high blood pressure and occasionally blood in their urine. Less commonly this condition is associated with blood clots forming in the legs or lungs.
How is membranous nephropathy diagnosed?
Generally, for a diagnosis of membranous nephropathy, you will need a kidney biopsy. You doctor will send the biopsy sample to a laboratory to look at the glomeruli under the microscope. However, by testing for certain antibodies in the blood this may be avoided in some cases.
What are the treatments for membranous nephropathy?
If caused by other conditions, such as infections, these need to be treated, which can be enough to cure the condition. In some patients, membranous nephropathy may improve by itself, and your doctor may wait a few months to see if this happens. In other cases, getting rid of the damaging antibodies needs immunosuppression treatment. There are several types of immunosuppressant treatments, and which one is used will depend on the individual.
Other treatments aim to improve the symptoms of membranous nephropathy, such as high blood pressure and swelling. These include:
- Water tablets (diuretics), which decrease the build-up of fluid in your body.
- Statins, medicines which lower cholesterol, which is often elevated in membranous nephropathy
- Medicines to decrease blood pressure, such as ACE inhibitors or angiotensin receptor blockers
- Diet changes to decrease salt intake
- Blood thinners may be needed in some cases to prevent or treat blood clots
In a proportion of patients, the filtering units are so badly damaged that kidney function worsens, and chronic kidney disease develops. In some cases, this leads to kidney failure. In these cases, treatment options include transplant, dialysis and conservative care.
What are the outcomes for membranous nephropathy?
The outlook for membranous nephropathy is different for each patient. In some cases, the disease may go away on its own. In others it may come and go after treatment, and for some it may last for many years. Membranous nephropathy can cause chronic kidney disease and in some cases kidney failure.
References
O’Brien, F. Membranous Nephropathy [online]. MSD Manual, Merck & Co, Inc., Rahway, NJ, USA; Apr 2025 [Accessed 17 February 2026]. Available from: Membranous Nephropathy - Genitourinary Disorders - MSD Manual Professional Edition
Alok, A. and Yadav, A. Membranous Nephropathy [online]. 2023. [Accessed 17 February 2026]. Available from: <PMCID: 32644595>
Reviewed May 2026 by reviewed by Professor Alan Salama, Professor of Nephrology
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