Reye Syndrome: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Reye Syndrome?
Reye syndrome is an emergency, so an emergency room doctor sees a child first. A pediatrician (a children's doctor) helps with care in the hospital. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is Reye syndrome?
Reye syndrome is a rare illness that affects the brain, the blood, and the liver. It usually happens when someone has just had a viral infection, such as a cold, the flu, or chickenpox. People with it often have low blood sugar and high levels of ammonia (a waste chemical) in the blood. This causes severe and sudden brain swelling.
Reye syndrome has become very rare, because doctors no longer recommend aspirin for routine use in children. It is most common during flu season in the fall and winter.
Symptoms
Children with Reye syndrome get sick very suddenly. They can start five to seven days after the viral illness begins. Symptoms may include:
- Nausea and vomiting that does not stop.
- Rapid breathing.
- Being unusually sleepy or sluggish.
- Sudden personality changes, such as being cranky or wanting to fight.
- Confusion or disorientation.
- Seizures.
- Loss of consciousness or coma.
People with Reye syndrome may bleed more if cut or injured, and blood may not clot or stop like it should.
Causes and who gets it
The cause of Reye syndrome is unknown. Studies link taking aspirin during a viral illness to getting it. Anyone can get Reye syndrome at any age, but it is most common in children and teens.
Some other medicines, such as Pepto-Bismol, and products with oil of wintergreen also contain aspirin-like chemicals.
Some children have MCAD deficiency, a rare problem in which the body cannot break down some fats for energy. For these children, aspirin during a viral illness is more likely to trigger Reye syndrome symptoms.
How doctors diagnose it
Reye syndrome is often hard to diagnose. It has the same symptoms as many other diseases. Two examples are encephalitis (brain swelling from infection) and meningitis (infection of the brain's lining). A doctor may suspect it when a viral illness is followed by vomiting or personality changes. Doctors may order these tests to rule out other disorders:
- Blood or urine tests to check ammonia levels in the blood or find toxins in the urine.
- An MRI or CT scan, which are pictures of the brain, to look for brain swelling.
- A spinal tap, which tests the fluid around the brain and spinal cord for swelling or infection.
- A screening test to rule out MCAD deficiency, a problem with burning fat for energy.
Treatment
There is no cure for Reye syndrome, but treatments can help manage symptoms and other conditions that may develop. A child with Reye syndrome goes to the intensive care unit (ICU) right away.
Treatment focuses on preventing brain damage by reducing brain swelling. It also aims to stop more damage to the liver and blood from lack of oxygen, and to prevent lung problems.
The care team may use breathing support, such as a breathing machine. They may give fluids through a vein (IV) with salts and sugar. They may also use steroids to reduce swelling in the brain. A hospital stay lasts from a few days up to a few weeks.
Many children recover completely, while others have lasting problems. These can include muscle weakness, nerve damage, memory loss, learning disabilities, and vision and hearing loss. Early detection and treatment greatly improve the rate of recovery and survival.
When to see a doctor
Go to the emergency room or call 911 right away if your child is confused or very sleepy, or has other mental changes. Also go to the nearest emergency department right away if any of the symptoms above appear soon after a viral illness. Reye syndrome can lead to seizures, loss of consciousness, a coma, and death.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. They can help you check medicine labels for aspirin. They can also talk about vaccines, which prevent many viral infections. Reye syndrome needs hospital care. These doctors can help with follow-up visits afterward.
Common questions
Does aspirin cause Reye syndrome?
Aspirin is linked to Reye syndrome, but experts do not know the exact cause. Because of this link, doctors recommend acetaminophen or ibuprofen instead of aspirin for children.
Can children recover from Reye syndrome?
Yes, many children recover completely from Reye syndrome, while others have lasting problems. Recovery depends on the amount of brain swelling and ammonia in the blood.
How can I prevent Reye syndrome?
To prevent Reye syndrome, never give a child aspirin unless the child's provider says so. Read medicine labels, because salicylate is also found in other over-the-counter medicines.
Is Reye syndrome common today?
No, Reye syndrome is very rare today. This is because aspirin is no longer recommended for routine use in children.
Sources
- National Institute of Neurological Disorders and Stroke - Reye's Syndrome
- MedlinePlus - Reye's Syndrome
- MedlinePlus - Reye syndrome (Medical Encyclopedia)
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
