Reye syndrome is a disease that affects all organs of the body. However, it is most harmful to the brain and liver. It can cause acute increase of pressure within the brain and massive increases in the liver. Reye syndrome commonly occurs during recovery from a viral infection, although it can also develop up to a week after the beginning of the viral illness. Symptoms may include persistent nausea, decline in alertness and loss of cognition, combative behavior and frequent lethargy. As the disease progresses, symptoms may include loss of consciousness or seizures.

Features include: initial normal development with onset varying from infancy to adolescence, vomiting, changes in consciousness sometimes amounting to coma, raised blood ammonia levels, fatty changes in the liver and other organs. In some cases: ammonia intoxication resulting in brain damage and intellectual and physical deterioration. Diagnosis can only be made with certainty by carrying out liver biopsy during the acute stage of the illness. The cause is not established, but onset has been observed after viral infection, suggesting that there may be an abnormal response or abnormal sensitivity to relatively common viral infections or toxins.

A specific disease process that can affect the liver, brain, pancreas, kidney, heart and muscle. It usually occurs in children under 18 years of age. It typically starts with a red rash, vomiting, and confusion that follows a viral infection. This can lead into seizures, coma, and breathing problems. The cause of Reye syndrome is not known although a variety of factors are thought to be involved, such as genetics or the use of aspirin during a viral illness. rooting - when a newborn turns his/her head toward touch near the mouth.