People with autism often don't respond to others' emotions. They may not realize how their behavior affects others. They find it hard to know what another person means through tone of voice or facial expressions. Children with autism often speak later than other children. They often have hearing problems. They may also rock, twirl their hair, or bang their head over and over again. Many people with autism also don't feel pain as strongly as others. They may have an abnormal response to sounds or touch.

You should have your child assessed for autism right away if any of these symptoms are present. Other behaviors that should raise concerns include:

• Possible deafness, or deafness that comes and goes
• The child used to speak but now does not
• The child doesn't smile when smiled at
• The child throws intense temper tantrums
• The child walks on their toes

A number of genes appear to play a role in autism. So do things in the environment. Research has found brain problems in people with autism. Nerve cells (neurons) in parts of the brain in a person with autism are smaller than normal. These cells have shorter nerve fibers than normal. These changes may mean that something got in the way of brain development of the fetus. Other studies have found problems with the signaling molecules in the brain of those with autism. Other disorders, such as Tourette syndrome, learning disabilities, and attention deficit disorder often occur with autism but don't cause it. About 1/3 of children with autism go on to develop epilepsy.

Some parents believe that the measles/mumps/rubella (MMR) vaccine caused their child's autism. But no scientific proof has been found to back this up. The symptoms of autism often appear around the same time as the MMR vaccine is given. But that doesn't mean the vaccine has caused the autism. There is no scientific proof that any vaccine or combination of vaccines causes autism.

Autism has no cure. But behavioral therapy and medicine may help ease symptoms. In behavioral therapy, therapists work 1-on-1 with children to help them develop social and language skills. The earlier a child is helped with this therapy, the better the outcome. Medicine may be prescribed to ease troublesome behavior or other symptoms of autism. The medicine affects the levels of signaling chemicals, such as serotonin, in the brain.