Nephrotic syndrome

Massive protein loss in the urine, causing swelling. In children it usually responds to steroids; the clue is puffy eyes in the morning.

What it is

A combination of heavy protein loss in the urine, low blood protein, and swelling.

In children it is most often minimal change disease, which responds well to steroids, and most children eventually grow out of it, though relapses are common along the way. In adults the causes are more varied and include diabetes, lupus, amyloidosis and various forms of glomerulonephritis, and a kidney biopsy is usually needed.

The characteristic early sign in a child is puffiness around the eyes on waking, which settles during the day as fluid redistributes, and is often mistaken for allergy. Swelling later moves to the legs, abdomen and genitals.

Three complications matter and each is under-recognised. Losing protein in the urine also means losing antibodies and clotting regulators, so there is a real risk of **serious infection**, particularly pneumococcal infection and peritonitis, and of **blood clots**. And **hypovolaemia**, where fluid sits in the tissues while the circulation is depleted, causes abdominal pain and cold peripheries and needs urgent treatment.

Vaccination, including pneumococcal, is important, and live vaccines must be avoided while on high-dose steroids.

Signs you might notice

Puffiness around the eyes, worse in the morning.

Swelling of the legs, ankles, abdomen and genitals.

Frothy urine.

Weight gain over days from fluid.

Tiredness, poor appetite.

Urgent, same day: fever or feeling unwell, because infection risk is high; severe abdominal pain, which may be peritonitis or hypovolaemia; breathlessness; or reduced urine output.

999: a swollen painful calf or sudden breathlessness, which may be a clot; or a child who is drowsy, has cold hands and feet, or severe tummy pain.

In a child with puffy eyes that is being treated as an allergy without improvement, ask for a urine dipstick.

How it can affect day-to-day life

Daily home urine dipstick testing is the routine for children with relapsing disease, and it is how a relapse is caught early. Parents become expert at it, and a written plan of what to do at what result is essential.

Steroids bring the usual burden: appetite, weight, mood swings, sleep disturbance and, over time, growth and bone effects. Parents find the behaviour changes particularly hard and are often not warned.

Salt restriction matters more than fluid restriction for the swelling.

Infection risk is the thing families most need to understand: fever is a reason to seek help, not to wait.

School absence and disruption is significant during relapses, and schools need to understand the urine testing and the steroid effects.

For adults, treating the underlying cause is the focus, and anticoagulation is sometimes given because the clot risk is substantial.

Supporting someone well

Ask for a urine dipstick in any child with unexplained puffiness, particularly around the eyes in the morning.

Learn home urine testing and follow the written relapse plan.

Reduce salt; it does more for the swelling than restricting drinks.

Treat any fever as urgent; do not wait it out.

Keep vaccinations up to date, including pneumococcal, and avoid live vaccines on high-dose steroids.

Watch for clot symptoms and act on them.

Ask about bone protection and growth monitoring during long steroid courses.

Weigh regularly; it is the most sensitive measure of fluid.

Tell the school, so testing and steroid effects are supported rather than questioned.

Where to get help

A GP practice for a urine dipstick and urgent paediatric or renal referral.

The renal team's number for suspected relapse or fever.

999 or A and E for severe abdominal pain, drowsiness, breathlessness or a swollen painful calf.

Kidney Care UK run a helpline and support families.