Autism is a lifelong disability characterized by severe defects in communication, socialization and repetitive and restricted behaviors interfering with education and functioning in society. Each individual will display communication, social, and behavioral patterns that are unique but fit into the overall diagnosis of autism. Those with autism will often have unusual responses to sensory experiences, such as certain sounds or the way objects look.
Symptoms also include problems with verbal and nonverbal communication as well as difficulties with repetitive behaviors or narrow, obsessive interests. These behaviors can range in impact from mild to severe and present in each individual with autism differently. Autism varies widely in its severity and symptoms that manifest in the individual. Scientists have not yet determined what causes this disorder.
(From: www.cdc.gov and www.nih.gov)