Symptoms and signs
Many children with glomerulonephritis may not notice any symptoms at first. The symptoms can vary from child to child. Examples are given below.
Blood in the urine
When red blood cells leak through the kidney’s filters into the urine, this causes haematuria (blood in the urine). Sometimes you cannot see the blood, but if there is a lot, the urine may be coloured red or dark brown (like blackcurrant squash or a cola drink).
Protein in the urine
When proteins leak through the kidney’s filters into the urine, this causes proteinuria (more protein in the urine than normal). You cannot usually see the protein, but occasionally it can make the urine look frothy. Protein is an important part of our diet and is in most foods. When we eat protein, it is digested (broken down) in the stomach and gut and taken into the blood.
Problems urinating
Some children urinate less often or pass smaller amounts.
Swelling
Some children have swelling or puffiness in different parts of their body, especially around their eyes, legs and feet (oedema).
Read more about why oedema happens
There are two reasons why children with glomerulonephritis get oedema.
- Sometimes, the damaged kidney filters (glomeruli) are not able to filter enough salt and water out of the blood into urine. After a while, there is too much salt and water in the body, which causes the swelling.
- Sometimes, the kidneys leak a large amount of protein, especially a type called albumin, into the urine. This leads to nephrotic syndrome. Fluid moves in and out of the bloodstream to nourish (feed) the body’s cells. Albumin helps keep fluid in the bloodstream – if there is not enough albumin, fluid stays outside the bloodstream and in parts of the body. This causes the swelling.
Swelling in the tummy and breathlessness
- A few children get a large swelling in their abdomen (tummy area). This is called ascites. It happens when fluid builds up in the area around the organs in the abdomen – the peritoneal cavity.
- A very small number of children feel breathless. This happens when fluid builds up in the area around their lungs.
If your child has glomerulonephritis and a very swollen tummy or feels breathless, contact your doctor as soon as possible.
Other symptoms and signs
The below are occasionally found in children with glomerulonephritis:
- feeling tired, low energy or difficulty concentrating
- decreased appetite (not wanting to eat)
- nausea (feeling sick) or vomiting (being sick), or diarrhoea
- pain in the tummy
- headaches that keep coming back or that do not go away.
- pain, stiffness or swelling of the joints.
Complications
Some children have more complications – health problems that happen because of the condition or its treatment. These are more rare. Your child’s healthcare team will carefully check for these, and speak with you about any treatment that your child may need.
High blood pressure
Glomerulonephritis can cause blood pressure that is too high, or hypertension. In some children, this causes headaches, vomiting or blurred (fuzzy) vision.
Nephrotic syndrome
If too much protein is lost in the urine, this causes nephrotic syndrome. Children with nephrotic syndrome often have oedema, which is swelling or puffiness, especially around their eyes or their legs and feet.
Rapidly progressive glomerulonephritis
Occasionally, glomerulonephritis gets worse quickly – this is called rapidly progressive glomerulonephritis (RPGN) or crescentic glomerulonephritis.
If this happens, your child will need to take medicines and may need more intensive treatment, such as dialysis, which uses special equipment to clean the blood. Some children with RPGN will get better, but a few will need long-term dialysis before they can have a kidney transplant.
This is one cause of acute kidney injury – when the kidneys quickly stop working as well as they should, over a short time.