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What is focal and segmental glomerulosclerosis?

Focal and segmental glomerulosclerosis (FSGS) is a medical term for a family of diseases involving damage to the glomeruli (the tiny filters in the kidney).

The damage causes scarring to the filters which then stop working properly. This allows protein to leak through the walls of the glomeruli and into the urine. The condition can affect children and adults.

Causes of focal and segmental glomerulosclerosis

FSGS can be caused by inherited diseases or by an immune dysfunction, where a part of the body’s immune system is over-active in a way that attacks the glomeruli. Sometimes the cause of FSGS is unknown.

Multiple outcomes

For some people FSGS may:

  • stop on its own and cause no further damage
  • remain unchanged for many years
  • get worse – especially if it is associated with high protein loss and severe fluid retention (known as nephrotic syndrome)
  • result in kidney failure – which can also be described as end-stage kidney disease (ESKD). This can lead to the need for kidney dialysis or a kidney transplant and the disease may also come back in the transplanted kidney.


Focal and segmental glomerulosclerosis symptoms

Some people may have no visible symptoms and may only discover that they have higher than normal amounts of protein in their urine (proteinuria) after a routine urine test.

In some cases, levels of protein loss and fluid retention can be so high that it causes puffiness (oedema) around the eyes, abdomen, feet and legs, and weight gain – nephrotic syndrome. Urine can also appear foamy.

If kidney failure is already well advanced symptoms could include tiredness and lack of energy, itching and muscle cramps.

Some people with FSGS may experience:

  • High blood pressure – which needs to be controlled to protect the kidneys from further damage and to reduce the risk of heart disease and stroke.
  • High cholesterol levels – which may need to be controlled with a special diet and cholesterol lowering drugs.
  • Low thyroid hormone levels – due to loss of thyroid hormone via the kidneys. This can be controlled by thyroid hormone supplements.

Focal and segmental glomerulosclerosis diagnosis

A kidney biopsy (a medical procedure to take small samples of the kidney away to look at under a microscope) may also be required to assess the extent of kidney scarring.

Blood and urine tests will also be used to gauge your kidney function and look for the presence of protein in your urine.

Genetic blood tests may also be carried out to see if your FSGS is an inherited strain. A kidney specialist will be able to give you advice about the chances of family members being affected, and whether screening should be offered to them.

Focal and segmental glomerulosclerosis treatment

Treatments (depending on the type and severity of FSGS) may include:

  • medicines such as ACE Inhibitors and ARBs to control blood pressure and protein loss
  • steroids to treat the symptoms of Nephrotic Syndrome and diuretics (water tablets) to reduce oedema
  • immunosuppressants (drugs that dampen down the immune system) may be used to treat steroid-resistant strains of FSGS and Nephrotic Syndrome
  • kidney removal
  • kidney dialysis (which may require you to restrict your diet)
  • kidney transplantation (but FSGS can sometimes come back in the new kidney)

Resources about focal and segmental glomerulosclerosis

If you have been diagnosed with FSGS and have any questions or concerns about your illness don’t hesitate to speak to your kidney specialist or your nurse specialist at your kidney unit.

You can find further information, advice and helpful tips in our Just diagnosed and How can I help myself? sections.

Reviewed April 2019

The need for more research

In the last few years, a lot of progress has been made on identifying the genetic mutations that cause inherited FSGS. We now need to work on understanding how to prevent these mutations damaging the kidney. Much more research is needed on what causes the immune form of FSGS, so that better treatments, with fewer side-effects, can be developed. We also need treatments that prevent the disease coming back in transplanted kidneys.

Our life-saving research is only possible with your support.

Save lives.

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