Hemolytic Uremic Syndrome

Hemolytic Uremic Syndrome (HUS)

Acronyms Medical

The hemolytic-uremic syndrome is characterized by severe changes and damage to the blood count, the vessels and the kidneys. EHEC is the best known form of hemolytic uremic syndrome.

What is hemolytic uremic syndrome?

Since hemolytic uremic syndrome (HUS) is usually a complication of severe bloody gastroenteritis with germs that produce the poison Shiga toxin, the actual symptoms of the syndrome usually appear together with bloody diarrhea, vomiting, nausea, abdominal cramps and fever.

According to abbreviationfinder, doctors define the haemolytic-uraemic syndrome (abbreviation: HUS) on the basis of three symptoms that occur together (“triad”):

  1. Decreased red blood cell count and capillary damage (microangiopathic hemolytic anemia)
  2. Decreased number of blood platelets or thrombocytes (thrombocytopenia; thrombocytes are blood cells involved in blood clotting)
  3. Acute kidney failureresulting in blood poisoning due to the accumulation of substances that the kidneys can no longer excrete

If only two of the three symptoms occur, doctors speak of “incomplete HUS”. According to the underlying causes, a distinction is made between the infectious and the non-infectious variant of the disease.

The haemolytic-uremic syndrome is also known as Gasser syndrome, named after the Swiss pediatrician Conrad Gasser (1912 – 1982), who first described (1955) the haemolytic-uremic syndrome.


Hemolytic-uremic syndrome most often occurs in the infectious form. Escherichia coli is often the causative agent. This bacterium is otherwise part of the healthy intestinal flora, but there are also malignant versions.

The dangerous strains are summarized under the well-known name EHEC (“Enterohaemorrhagic Escherichia coli”). Occasionally, other bacteria such as salmonella are also responsible for HUS. Viruses are rarely a possible trigger. These include, for example, the varicella-zoster virus, which also causes herpes and shingles. The dreaded HI virus can also be responsible for HUS.

Non-infectious HUS is often triggered as a side effect of various medications. HUS can also occur as a pregnancy-related complication (“gestosis”). In addition, genetic disorders of blood coagulation also cause the haemolytic-uraemic syndrome.

Symptoms, Ailments & Signs

Since hemolytic uremic syndrome (HUS) is usually a complication of severe bloody gastroenteritis with germs that produce the poison Shiga toxin, the actual symptoms of the syndrome usually appear together with bloody diarrhea, vomiting, nausea, abdominal cramps and fever. However, there are also atypical cases of this disease caused by other causes.

In these forms of hemolytic-uremic syndrome, the symptoms of gastroenteritis are absent. The actual symptoms of HUS are bloody urine, punctate skin and mucous membrane bleeding (petechiae), palpitations (tachycardia), lethargy, pallor, physical weakness, high blood pressure and jaundice. Liver and spleen are enlarged.

The bleeding is caused by the excessive consumption of the clotting factors. At the same time, there is increased hemolysis (increased breakdown of red blood cells). The bilirubin released in the process causes jaundice with yellowing of the skin and eyes. Overall, this is an extremely life-threatening condition that requires immediate medical attention.

Otherwise, the risk of dangerous complications such as irreversible kidney failure, abdominal dropsy (ascites), accumulation of fluid in the pericardial sac (pericardial effusion), electrolyte imbalance or seizures and even coma is increased. With symptomatic therapy, up to 80 percent of the diseases heal again. In severe cases, however, a kidney transplant is necessary to save the patient’s life. Chronic kidney damage and arterial hypotension sometimes remain as secondary damage.

Diagnosis & History

Doctors primarily diagnose hemolytic-uremic syndrome based on blood laboratory values. Erythrocytes and thrombocytes (red blood cells and blood platelets) are reduced with a simultaneous increase in some metabolic breakdown products.

In the urine, on the other hand, proteins and blood cells can be detected in increased amounts. Finally, pathogens in the intestine can be found with a stool sample. The physicians recognize kidney damage with the sonographic representation (ultrasound).

In the course of the haemolytic-uraemic syndrome, damage to the intestinal epithelium (uppermost layer of the intestinal mucosa) occurs first. This leads to diarrhea and the entry of toxins into the bloodstream. There the vessel walls and finally the kidneys are attacked. Life-threatening complications can occur as the disease progresses. These include high blood pressure and fluid retention in the abdominal cavity and pericardium.

Seizures have also been described as a consequence of HUS. About half of all patients suffer from chronic renal dysfunction after surviving the disease. About 3% of all cases of hemolytic-uremic syndrome end fatally.


This syndrome usually causes various blood disorders. These can extremely reduce the quality of life of the patient and also make everyday life considerably more difficult. In most cases, various toxins enter the blood and can lead to acute poisoning. The patients suffer from pain and shortness of breath and, in the worst case, can even die.

It is not uncommon for the syndrome to also lead to high blood pressure, which can promote a heart attack. This can also lead to life-threatening conditions and further to the death of the patient. If left untreated, this syndrome usually leads to a reduction in life expectancy. Patients also suffer from cramps and kidney problems.

Treatment usually does not lead to further complications or symptoms. Blood poisoning can be treated with antibiotics, although the further course of the disease depends on the severity of the poisoning. A positive course of the disease cannot be guaranteed. A healthy diet and lifestyle can also contribute to accelerated healing.

When should you go to the doctor?

If symptoms such as nausea and vomiting, diarrhea or stomach pain are noticed, a doctor should be consulted. If the symptoms persist for several days or rapidly increase in intensity, a doctor’s visit is also indicated. If blood is noticed in the urine or stool, you should go to your family doctor or a urologist on the same day. The same applies if incontinence is suddenly detected or severe cramps occur for which there is no clear underlying cause.

If muscle problems or seizures occur, this must be clarified medically. The same applies to severe tiredness and exhaustion, possibly associated with high blood pressure or cardiovascular disorders. Dizziness, severe fever or persistent insomnia are best clarified in a hospital. In the event of behavioral problems or depressive moods, a therapist can be consulted. Since the haemolytic-uraemic syndrome can cause serious complications including a heart attack, you must go to your family doctor or an internist at the first suspicion. Children should be presented to the pediatrician as soon as possible.

Treatment & Therapy

The hemolytic-uraemic syndrome is usually not causally treatable. In the case of bacterial-infectious HUS, even the medication of antibiotics is risky since the release of bacterial toxins can still increase.

If bacterial blood poisoning occurs, there is no alternative to administering antibiotics. In some cases, replacing the blood plasma with transfusions is helpful. If drugs are the cause of non-infectious HUS, the drug must be discontinued.

In intensive care monitoring, doctors try to combat the most serious consequences of HUS. The high blood pressure that occurs requires drug intervention, and the electrolyte balance (minerals) must also be monitored and controlled.

Blood washing (dialysis) is often necessary in order to remove metabolic toxins and bacterial toxins from the body by filtration. In extreme cases, accumulations of fluid in the abdominal cavity and in the pericardium must be relieved by punctures. Sometimes there is a need for a kidney transplant after a hemolytic-uremic syndrome has been experienced.


The hemolytic-uraemic syndrome in the infectious form can be prevented by hygienic measures. In the course of the EHEC wave of 2011, the health authorities repeatedly pointed out that various foods suspected of being germ carriers should be avoided.

Increased kitchen hygiene was called for when preparing raw meat or fresh vegetables. Baby food should only consist of cooked ingredients because infants are among the main risk patients due to their increased intestinal sensitivity.

In addition, caution was required after staying in busy places: washing and disinfecting hands also served to prevent haemolytic-uraemic syndrome.


Medical follow-up and monitoring is required after treatment of hemolytic-uremic syndrome. In this way, dangerous complications can be quickly identified and combated. The patients themselves have limited options, so they should listen to the doctor’s advice and have regular check-ups. Careful monitoring can determine whether the state of health has improved or deteriorated.

The doctor adjusts the treatment with the appropriate medication precisely to the severity of the disease. Other medicines may also need to be discontinued. In the context of inpatient care, particularly careful monitoring of the patient is possible. Accompanying measures often take place here, such as dialysis or special surgical interventions. The body needs enough rest during this time.

In addition, those affected should avoid mental stress in order to protect themselves. Hygiene is particularly important, because the disease syndrome often occurs in an infectious form. Certain foods can contain germs that are particularly dangerous for patients. Improved kitchen hygiene and not eating fresh, uncooked vegetables reduce the risk. Babies in particular are at great risk, so parents should be careful and ensure thorough disinfection.

You can do that yourself

The haemolytic-uremic syndrome always requires intensive medical monitoring, as otherwise the disease often leads to life-threatening complications in the patient. The options for self-help are correspondingly limited, since the focus is on medical instructions and patients under no circumstances check their state of health on their own. Those affected usually receive special medication, which must be discontinued in certain manifestations of the hemolytic-uremic syndrome. As a result, the patients are often in inpatient care and follow the instructions of the hospital staff.

Sometimes therapeutic measures such as dialysis or surgery are necessary. It is then important that patients with haemolytic-uremic syndrome allow their bodies to rest and avoid mental stress. Meticulous hygiene is also of fundamental importance. Inadequate hygienic standards are often the cause of the onset of hemolytic-uremic syndrome.

Patients pay attention to thorough personal hygiene and, in particular, to the cleanliness of the food they eat. The origin and type of preparation of the food are particularly important in order to prevent infection with other germs. During the hospital stay, patients usually receive special meals that meet hygienic standards. After discharge, it is important that the patients also implement appropriate hygiene measures at home.

Hemolytic Uremic Syndrome