ASD is a complex developmental disorder that affects how a person behaves, interacts with others, communicates, and learns. NICHD is one of many federal agencies and NIH Institutes working to understand ASD. NICHD supports and conducts research on what causes autism, how best to detect signs of autism, how best to treat autism and its symptoms, and other topics.
Autism spectrum disorder (ASD) is a complex neurological and developmental disorder that begins early in life and affects how a person acts, learns, and interacts with others.
Symptoms of autism range from poor eye contact, repetitive behaviors, and "tuning people out" to intense tantrums and high sensitivity to noise.
The behavioral symptoms of autism often appear early in development. Many children show symptoms of autism by 12 months to 18 months of age or earlier.
Scientists don't know exactly what causes autism. Because the disorder is so complex and no two people with autism are exactly alike, there are probably many causes for autism.
Researchers don't know exactly how many people in the United States have autism. The latest estimates suggest that about one out of every 68 children in the United States currently has autism.
Health care providers look for certain symptoms or groups of symptoms to diagnose autism spectrum disorder (ASD). If you have concerns about your child's development, talk to his or her health care provider right away.
Find answers to other common questions about autism, such as what other conditions are associated with it and what impact new diagnostic criteria may have on people with ASD.