Hemolytic Uremic Syndrome – Symptoms and Causes

ByJanis Updated

Overview

Hemolytic uremic syndrome (HUS) is a serious condition where small blood vessels become damaged and inflamed, causing blood clots throughout the body. These clots can harm the kidneys and other organs, potentially leading to kidney failure.

HUS can affect anyone, but children under five years old face the highest risk. The most common trigger is infection with specific strains of E. coli bacteria. However, several other factors may cause HUS:

  • Other types of infections
  • Certain medications
  • Pregnancy complications
  • Cancer
  • Autoimmune diseases
  • Genetic mutations

Despite its severity, HUS has a good prognosis when treated promptly. Most patients, especially young children, recover completely with proper medical care.

Early recognition of symptoms is crucial for successful treatment. These may include:

  • Bloody diarrhea

  • Decreased urination

  • Fatigue

  • Pale skin

  • Unexplained bruising

Signs and Symptoms

Hemolytic uremic syndrome (HUS) shows different symptoms based on what causes it.

When caused by E. coli bacteria, early signs may include:

  • Bloody diarrhea
  • Stomach pain, cramping, or bloating
  • Fever
  • Vomiting

As the condition progresses, it damages blood vessels, causing red blood cells to break down (anemia) and creating blood clots that harm the kidneys. These changes lead to:

  • Pale skin
  • Severe fatigue
  • Easy bruising
  • Unusual bleeding from nose or mouth
  • Reduced urination or blood in urine
  • Swelling in legs, feet, or ankles (and sometimes face, hands or entire body)
  • Confusion, seizures, or stroke
  • High blood pressure

When Medical Help Is Needed

Seek medical attention immediately if you or your child experiences bloody diarrhea or several days of diarrhea followed by:

  • Decreased urination
  • Swelling in any part of the body
  • Unexplained bruising
  • Unusual bleeding
  • Extreme tiredness

Important: Get emergency care if urination stops for 12 hours or longer. This is a serious warning sign that requires immediate medical attention.

What Causes HUS?

Hemolytic uremic syndrome (HUS) most often happens after an infection with certain E. coli bacteria. These specific bacteria make Shiga toxin and are called Shiga toxin-producing E. coli (STEC). This cause is particularly common in children under 5 years old.

Most E. coli types are harmless. Only certain strains can lead to HUS.

Other possible causes include:

  • Different Infections:
    • Pneumococcal bacteria
    • HIV
    • Flu viruses
  • Medication-Related:
    • Some cancer treatments
    • Certain anti-rejection drugs for organ transplants
  • Health Complications:
    • Pregnancy (rarely)
    • Autoimmune diseases
    • Cancer

There is also a less common form called atypical HUS that can run in families. People who inherit the gene for this type don’t always develop the condition.

However, certain triggers like infections, medications, or ongoing health problems can activate HUS in people who carry this gene.

Risk Factors

People can get hemolytic uremic syndrome from E. coli through several ways:

  • Eating contaminated food like meat, fruits, or vegetables
  • Swimming in water with infected feces
  • Close contact with someone who has the infection

Some people face higher risks than others:

  • Young children (age 5 and under)
  • People with weakened immune systems
  • Individuals with certain genetic variations

Complications

Hemolytic uremic syndrome can lead to several serious health problems.

The kidneys may fail rapidly (acute failure) or gradually (chronic failure). Blood pressure may rise to dangerous levels.

Brain-related complications include strokes, seizures, and coma. Patients might experience bleeding due to clotting disorders.

Heart function can become impaired. The digestive system may also suffer damage, affecting the intestines, gallbladder, and pancreas.

Prevention

You can’t always tell if food has E. coli by how it looks, smells, or feels. Follow these safety steps to protect yourself and others:

Food Safety Practices

  • Drink only pasteurized milk, juice, and cider

  • Cook meat thoroughly to at least 160°F (71°C)

  • Defrost meat in the refrigerator or microwave, not on countertops

  • Store raw meat below produce in your refrigerator to prevent dripping

  • Keep raw foods separate from ready-to-eat foods

  • Never place cooked food on plates that held raw meat

Proper Hygiene

  • Wash hands thoroughly before eating
  • Clean hands after using restrooms or changing diapers
  • Sanitize kitchen surfaces and utensils regularly

Water Safety

  • Avoid swimming in unclean water
  • Don’t swim when experiencing diarrhea

By following these guidelines, people can help protect themselves and their families from potentially serious health problems.

Health Writer

Janis's areas of expertise include nutrition, exercise, stress management, and mental health. She is passionate about educating and empowering people to take control of their health and make positive changes that can last a lifetime. Janis believes that small, sustainable changes are the key to long-term success, and she works with her clients to develop personalized plans that fit their individual needs and lifestyles.