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Hemolytic Uremic Syndrome - Symptoms, Causes, Complications, and Prevention

Published on Sep 30, 2022   -  4 min read


Hemolytic uremic syndrome (HUS) is a disorder in which the kidney's tiny blood capillaries become damaged and irritated.

What Is Hemolytic Uremic Syndrome?

A hemolytic uremic syndrome is a complicated illness in which an immunological response, usually triggered by a gastrointestinal tract infection, results in low red blood cell levels, low platelet levels, and kidney impairment.

The most common cause of this syndrome is gastrointestinal tract infections (infections of the stomach and intestines). Toxins generated during an intestinal bacterial infection cause the immune system to react. Blood cells are damaged and destroyed as they flow through the blood vessels as a result of this. Red blood cells (RBC) and platelets are among those affected, and they die early. There are two ways in which the kidney is impacted. Kidney injury can occur due to the immune response causing direct damage to kidney cells.

On the other hand, a build-up of damaged RBCs or platelets might block the kidney's filtering system, causing kidney injury or a build-up of waste products in the body since the kidney can no longer adequately clear waste from the blood. If left untreated, a kidney injury might be fatal. If HUS progresses without therapy, it can lead to kidney failure, dangerously high blood pressure, heart issues, and stroke. In children, HUS is the most common cause of acute renal failure. It is most frequent in children under five, but it can also affect older children and adults. Fortunately, most people who receive quick treatment can recover without any long-term effects on their kidneys.

What Are the Symptoms of Hemolytic Uremic Syndrome?

Depending on the cause of HUS, the indications and symptoms may differ. The majority of instances of HUS are caused by E. coli bacteria infection, which affects the digestive tract first.

The following are some of the first indications and symptoms of this type of HUS:

  • Fever

  • A kind of diarrhea that is often bloody.

  • Abdominal pain, bloating, and cramping.

  • Vomiting

The blood vessels are damaged in all kinds of HUS, regardless of the etiology. This damage results in the breakdown of red blood cells (anemia), the formation of blood clots in the blood arteries, and kidney injury.

The following are signs and symptoms of these changes:

What Are the Causes of Hemolytic Uremic Syndrome?

The most common cause of HUS is infection with certain varieties of Escherichia coli (E. coli) bacteria, particularly in children under five. Escherichia coli is a type of bacteria found in the intestines of healthy humans and animals. The vast majority of the hundreds of E. coli strains are normal and harmless. However, some E. coli strains cause diarrhea. Shiga toxin is produced by some of the E.coli strains that cause diarrhea. Shiga toxin-producing E. coli, or STEC, is the name given to these strains. When a person becomes infected with a strain of STEC, the Shiga toxin enters the bloodstream and damages their blood vessels, potentially leading to HUS. However, most people infected with E. coli, even the most dangerous strains, do not develop HUS.

Other causes of HUS include infections such as pneumococcal bacteria, the human immunodeficiency virus (HIV), or influenza. Certain medications, particularly those used to treat cancer and suppress organ transplant recipients' immune systems. HUS can be a pregnancy complication or result from a medical condition such as autoimmune disease or cancer. Atypical HUS is a rare type of HUS that can be passed down genetically to children. People who inherit the mutated gene that causes this type of HUS are unlikely to develop the condition. However, the mutated gene may be activated after exposure to a trigger, such as an infection, using certain medications, or developing a chronic health condition.

Who Is the Population at Risk for Developing Hemolytic Uremic Syndrome?

Most HUS cases are caused by bacterial infection with specific strains of E. coli. Individuals can become infected with E. coli if they:

  • Consume contaminated meat or produce.

  • Swim in feces-contaminated pools or lakes.

  • Have close contact with an infected person, such as within a family or at a childcare facility.

The following people have a higher tendency to develop HUS:

  • Children under the age of five.

  • Adults over the age of 65.

  • Individuals with a compromised immune system.

  • People who have specific genetic changes that make them more prone to HUS.

What Are the Complications?

HUS can result in life-threatening complications such as:

  • Kidney failure can occur suddenly (acutely) or gradually over time (chronic).

  • High blood pressure.

  • Seizures or stroke

  • Coma.

  • Clotting issues that result in bleeding.

  • Heart issues.

  • Digestive tract issues, such as intestine, gallbladder, or pancreas problems.

How Can Hemolytic Uremic Syndrome Be Prevented?

  • Meat or produce tainted with E. coli may not appear, feel, or smell bad. To avoid E. coli infection and other foodborne illnesses, follow these steps:

  • Unpasteurized milk, juice, and cider should be avoided.

  • Hands should be thoroughly washed before eating and after using the restroom and changing diapers.

  • Clean utensils and food surface regularly.

  • Cook the meat until it reaches an internal temperature of at least 160 degrees Fahrenheit.

  • Meat can be defrosted in the microwave or refrigerator.

  • Separate raw foods from ready-to-eat foods. Cooked meat should not be served on plates that have previously been contaminated with raw meat.

  • Refrigerate meat beneath produce to reduce the risk of liquids such as blood dripping on produce.

  • Avoid filthy swimming areas. If a person has diarrhea, they must avoid swimming.


Once the syndrome has been initiated, no known treatment can stop it. The doctor must distinguish between this disease and a similar condition known as thrombotic thrombocytopenic purpura, which has a specific treatment. Most treatments aim to alleviate the symptoms and signs of this disease while preventing further complications.

This could include:

  • High blood pressure treatment.

  • Maintaining specific fluid and salt levels.

  • Transfusions of blood.

  • Dialysis for kidneys.

  • Medications.

The majority of children with HUS recover entirely. However, some people will suffer long-term kidney damage.

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Last reviewed at:
30 Sep 2022  -  4 min read




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