Skip to main content

LEARN Oxalosis & Hyperoxaluria

We need your help

hyperoxaluria H1

What is hyperoxaluria? 

(hyper – oxal – uria)

What is oxalosis? 

Oxalosis occurs when the kidneys stop eliminating calcium oxalate crystals from the body through the urine. Because the kidneys stop working, the oxalate crystals build up in other places in the body. In its late stages, oxalosis affects more than a person’s kidneys. 

What causes these conditions? 

Hyperoxaluria can be caused by a genetic disorder, eating too many oxalate-rich foods or an intestinal disease. In some people the cause of the disease is not known but may result from changes in the way kidneys handle normal amounts of oxalate. Early diagnosis and treatment are important to the long-term health of your kidneys.

What is Primary Hyperoxaluria (PH)?

PH is a family of rare, genetic liver disorders that can damage the kidneys. The liver normally makes proteins, called enzymes, that prevent the body from making too much oxalate.

In PH, the liver doesn't create enough of this enzyme, or the enzyme doesn't work properly. For people with PH, their diet does not have a big effect on the amount of oxalate in their body. PH is very rare and occurs in just 1 to 3 people out of a million with a higher prevalence in some regions, such as the Middle East and North Africa. In the United States and Europe, there may be approximately 2,500 to 5,000 cases. People of any age may have PH. There are 3 separate types of PH, and each one is related to problems with a specific enzyme in the liver.

These enzymes are:

  • PH1: alanine-glyoxylate aminotransferase, or AGT
  • PH2: glyoxylate/hydroxypyruvate reductase, or GR/HPR
  • PH3: 4-hydroxy-2-oxoglutarate aldolase, or HOGA

In some patients with PH, a genetic mutation has not been identified.These individuals are often referred to as having idiopathic PH or “no mutation detected” PH.

Read less Read more

Enteric Hyperoxaluria

Enteric hyperoxaluria, sometimes known as secondary hyperoxaluria, is caused by the body absorbing too much oxalate from the food people eat. This may happen because a person has another condition in their gastrointestinal tract, like gastric bypass, Crohn’s disease, short bowel syndrome, or other conditions. For people with enteric hyperoxaluria, eating foods that are low in oxalate is very important. You can find a list of these foods here.

Read less Read more


Oxalosis is typically caused by kidney failure due to hyperoxaluria. Oxalosis in its late stages can cause a variety of complications beyond those with the kidneys. Complications can include bone disease, anemia, skin ulcers, heart and eye problems, and, in children, a failure to develop and grow normally.

Read less Read more

What are the symptoms? 

When a person with PH1 has a kidney stone, symptoms can include: • Flank pain • Urinary tract infections • Painful urination • Blood in the urine

People with PH1 often experience the formation of oxalate stones throughout the urinary tract and kidneys. Most often, kidney stones are the first sign of hyperoxaluria. Kidney stones are uncommon in childhood. For this reason, all young people with kidney stones should have a complete evaluation by a doctor.

Symptoms of a kidney stone may include:

  • Severe or sudden abdominal pain or pain in the side
  • Blood in the urine
  • Urinary tract infection
  • Frequent urge to urinate
  • Pain when urinating
  • Fever and chills

Some individuals are not diagnosed until after their kidneys have failed, and they require dialysis to help filter waste products from the blood.

Untreated primary hyperoxaluria can eventually damage a person’s kidneys and they may stop working. For some people, this is the first sign of the disease.

Symptoms of kidney failure may include:

  • Decrease in urine amount or not being able to urinate at all
  • Feeling generally ill or tired, or having heavy fatigue
  • Loss of appetite, nausea, and vomiting
  • Pale skin color related to anemia

Oxalosis in its late stages can cause a variety of complications in addition to those with the kidneys. This can include bone disease, anemia, skin ulcers, heart and eye problems, and, in children, a failure to develop and grow normally.