Reye's Syndrome: 15 Symptoms Worth Looking Out For

Reye’s syndrome is rare—but when it strikes, it escalates fast. Most often affecting children and teenagers recovering from viral infections like the flu or chickenpox, this condition causes dangerous swelling in the brain and liver. And while the initial symptoms might mimic common post-viral fatigue or stomach flu, the consequences can be life-threatening. Confusion, seizures, hallucinations, even persistent vomiting—these aren’t just symptoms. They’re red flags. Immediate medical intervention can make the difference between full recovery and permanent damage. One major risk factor? Aspirin (acetylsalicylic acid). Even small doses, if given during or after a viral illness, can trigger this severe reaction. That’s why understanding the warning signs matters more than ever. We’ve expanded our list to 15 critical symptoms of Reye’s Syndrome you need to watch for, breaking down what they mean and why they shouldn’t be ignored. Because when it comes to your child’s brain and liver, every second counts—and every symptom tells a story.

1. Swollen Liver

When Reye's syndrome sets in, the patient's blood sugar will usually drop. At the same time, acidity and ammonia levels in the blood rise, and the liver may swell up and develop fatty deposits. There are multiple potential liver complications of Reye's syndrome. In addition to fatty deposits, patients may have abnormal liver function tests. If the liver stops performing its usual functions, this can lead to the accumulation of toxic substances in the blood. In serious cases, the liver fails entirely. Liver failure is a condition where the liver has lost enough function that it cannot perform lifesaving functions. Patients with failing livers may exhibit bleeding and poor blood clotting. Typically, liver failure must be treated with a liver transplant.