What are the symptoms of hemorrhagic fever with renal syndrome?

Hemorrhagic Fever with Renal Syndrome, also known as Epidemic Hemorrhagic Fever, presents with the following symptoms: 1. Febrile stage: Patients often experience sudden high fever, with body temperature reaching 39~40℃, accompanied by headache, lumbar pain, and orbital pain (known as the "three pains"), as well as facial flushing, neck redness, and upper chest redness (known as the "three reds"). This stage may also present with symptoms such as nausea, vomiting, abdominal pain, and diarrhea. Some patients may exhibit petechiae on the skin and mucous membranes. 2. Hypotensive shock stage: This typically occurs during the later phase of fever or during defervescence. The patient's blood pressure drops significantly, and symptoms of shock such as poor tissue perfusion, coma, and respiratory distress may occur, endangering life. 3. Oliguric stage: Due to impaired kidney function, urine output decreases markedly, which may lead to electrolyte disturbances and metabolic acidosis. In severe cases, uremia may develop. 4. Diuretic stage: Urine output gradually increases, reaching up to 4000~8000ml per day, potentially leading to hypovolemia. Complications such as shock and hypokalemia must be carefully monitored. 5. Convalescent stage: Symptoms gradually subside, urine output returns to normal, and kidney function recovers progressively. The disease course is relatively long, lasting 1 to 3 months.