Learn about symptoms, causes, diagnosis and treatment for this rare kidney disorder, which develops in people who have too much oxalate in the urine.
Hyperoxaluria occurs when you have too much oxalate in your urine. Oxalate is a natural chemical in your body, and it's also found in certain types of food. But too much oxalate in your urine can cause serious problems.
Hyperoxaluria can be caused by inherited (genetic) disorders, an intestinal disease or eating too many oxalate-rich foods. The long-term health of your kidneys depends on early diagnosis and prompt treatment of hyperoxaluria.
Oxalosis happens after the kidneys fail in people who have primary and intestinal causes of hyperoxaluria, and excess oxalate builds up in the blood. This can lead to oxalate deposits in blood vessels, bones and body organs.
Often, the first sign of hyperoxaluria is a kidney stone. Symptoms of a kidney stone can include:
Kidney stones in childhood are uncommon. Kidney stones that form in children and teenagers are likely to be caused by an underlying condition, such as hyperoxaluria.
All young people with kidney stones should see a doctor for a thorough evaluation, including a test that measures oxalate in the urine. Adults with recurrent kidney stones also should be evaluated for oxalate in the urine.
Hyperoxaluria occurs when there is too much of a substance called oxalate in the urine. There are several types of hyperoxaluria:
Primary hyperoxaluria. Primary hyperoxaluria is a rare inherited (genetic) condition present at birth. In this type, the liver doesn't create enough of a certain protein (enzyme) that prevents overproduction of oxalate, or the enzyme doesn't work properly. Excess oxalate is eliminated through your kidneys, in your urine. The extra oxalate can combine with calcium to create kidney stones and crystals, which can damage the kidneys and cause them to stop working (renal failure).
Kidney stones form early and most often cause symptoms during childhood or adolescence. Because of the very large amounts of oxalate produced, the kidneys of many people with primary hyperoxaluria fail by early to middle adulthood. But renal failure can occur as early as infancy, while others with primary hyperoxaluria never develop kidney failure. To date, experts have identified three different genetic causes of primary hyperoxaluria.
Untreated primary hyperoxaluria can eventually damage your kidneys. Over time your kidneys may stop working. For some people, this is the first sign of the disease.
Signs and symptoms of kidney failure include:
Oxalosis in its late stages can cause a variety of complications outside the kidney, including bone disease, anemia, skin ulcers, heart and eye problems, and in children, a failure to develop and grow normally.
Your doctor will conduct a thorough physical exam, including a medical history and discussion of your diet. Tests to diagnose hyperoxaluria may include:
After initial testing, your doctor may recommend more tests to confirm the diagnosis and see how the disease has affected other parts of your body. These tests may include:
If you're diagnosed with primary hyperoxaluria, your siblings are at risk of the disease and should be tested as well. If your child has primary hyperoxaluria, you may want to consider genetic testing if you plan to have more biological children. Medical genetics counselors experienced in hyperoxaluria can help guide your decisions and testing.
Treatment depends on the type, symptoms and severity of hyperoxaluria and how well you respond to treatment.
To reduce the amount of calcium oxalate crystal formation in your kidneys, your doctor may recommend one or more of these treatments:
Kidney stones are common in people with hyperoxaluria, but they don't always need to be treated. If large kidney stones are causing pain or blocking urine flow, you may need to have them removed or broken up so they can pass in the urine.
Depending on the severity of your hyperoxaluria, you may eventually lose kidney function. Kidney dialysis may help temporarily, but it doesn't keep up with the amount of oxalate produced. A kidney transplant or kidney and liver transplant can cure certain inherited types of hyperoxaluria (primary hyperoxaluria).
For treatment of kidney stones associated with hyperoxaluria, you may start by seeing your family doctor. If you have large, painful kidney stones or stones that are damaging your kidneys, your doctor may refer you to a doctor who specializes in treating problems in the urinary tract (urologist or nephrologist).
To prepare for your appointment:
For hyperoxaluria, some basic questions include:
Besides the questions you prepare in advance, don't hesitate to ask other questions during your appointment as they occur to you.
Your doctor may ask questions such as:
July 14th, 2021