HUS often begins with vomiting and diarrhea, which may be bloody. Within a week, the person may become weak and irritable. Persons with this condition may urinate far less than normal. Urine output may almost stop.

Red blood cell destruction leads to symptoms of anemia.

Early symptoms:

• Blood in the stools
• Irritability
• Fever
• Lethargy
• Vomiting and diarrhea
• Weakness

Later symptoms:

• Bruising
• Decreased consciousness
• Low urine output
• No urine output
• Paleness
• Seizures -- rare
• Skin rash that looks like fine red spots (petechiae)
• Yellow skin (jaundice)

The health care provider will perform a physical exam. This may show:

• Liver or spleen swelling
• Nervous system changes

Laboratory tests will show signs of hemolytic anemia and acute renal failure. Laboratory tests may include:

• Blood clotting tests (PT and PTT)
• Chem-20 may show increased levels of BUN and creatinine
• Complete blood count (CBC) may show increased white blood cell count and decreased red blood cell count
• Platelet count
• Urinalysis may reveal blood and protein in the urine
• Urine protein test can be used to show the specific amount of protein in the urine

Other tests:

• Kidney biopsy
• Stool culture may be positive for a certain type of E. coli bacteria or other bacteria