Autism is not simply one disorder, but a group of developmental disorders known as autism spectrum disorders, as explained by the Mayo Clinic. Typically diagnosed before a child is 3 years old, autism has symptoms that affect a child's ability to communicate and interact with other people. Although every child's symptoms vary in severity, they are characterized into three basic categories.
Communication
Autism affects a child's ability to communicate, both verbally and non-verbally. Depending on the severity of your child's symptoms, you may notice that his speech is delayed or completely absent. When he does speak, he may use repetitive words or phrases that he has heard many times. And while he is saying these words or phrases, he usually does not understand how to use them appropriately.
When it comes to non-verbal communication, he may not have any facial expression or may have an inappropriate facial expression, such as a scowl when you are trying to make him smile. Many children are able to wave goodbye by age 1, but children with autism are not capable of this simply because they cannot understand this method of communicating.
Social
Social skills may be the hardest for parents to cope with, as this is when displaying signs of affection come into play. As an infant, a baby's face typically lights up around the age of six months whenever a parent walks in the room. However, you may notice that your baby is not doing this. As she becomes older and you attempt to cuddle or hold her, she may stiffen her body or pull away from you as if she does not want you to hug or kiss her. This is because she does not understand emotion.
When taking her to play with other children, you may realize that she prefers to play alone and never engages in play with other children. As explained by HelpGuide, children with autism have a difficult time making friends, engaging in play and showing emotion.
Perhaps one of the most obvious signs of this disorder is a child's inability to recognize her own name. By the age of 2 at the very latest, your child should look at you when you say her name. Children with autism will not respond, according to the Mayo Clinic.
Behavior
A child with autism likes set routines. If you have set his breakfast at a certain time and his bath time at another, he will become disturbed, if not inconsolable, when these routines are broken. Some autistic children begin screaming or rocking back and forth when faced with change, no matter how slight it might be.
You may also notice that even during moments of calm, a child with autism might rock back and forth for long periods of time or flap his hands endlessly. These are all behaviors typical of children with autism.
When playing, a child with autism will undoubtedly become fascinated with one object, such as a particular car or block. Rather than jump from one toy to another, as most children do, he will play for hours with this particular object. He may even take all the cars or blocks he has and line them up meticulously; should anyone accidentally disturb this line, he will become emotionally inconsolable.


