The symptoms of autism and PDD are hard to understand. These children seem to have less control over their emotions, they perceive in odd ways and their understanding seems severely impaired compared to their concrete skills. They seem to have special problems in learning language and social skills. You will find a child having difficulties in most or all of these areas:
 
Language
All children communicate, but children with autism or PDD have special problems. Some never learn to use spoken language, while others will only learn the basic language specific to their needs. A child may mostly repeat what he hears (echolalia). Others develop advanced speech, but have problems if affect, in their ability to express feelings or ideas, or in knowing the right way or time to say things.
 

Social
The actions of others are confusing to these children and they may withdraw from social interactions. Many have difficulty with interactive play. They may have difficulty picking up social clues so their actions may not be appropriate for the situation.
 
Recreation
With their difficulty understanding abstract ideas, these children usually prefer and learn best through the concrete. Some show little imaginative play, some have imaginative play, but it tends to follow set themes or interests. Many prefer to repeat the same Recreation over and over. The child may even "withdraw into himself", engaging in repetitive self-stimulation such as rocking or rhythmic moving of the hands.
 
These children often seek out the security of routines, and can become very dependent on them. They may avoid new experiences or situations.
 
Perceptions
It appears both from the observations of others and by first person accounts that these children often experience perceptions differently. Sights, sounds, textures that we easily accept can cause anxiety and even rage in a child. One child, for example, said that red hurt his eyes. Another flew into a rage when she felt the "prickle" of wool. Yet other experiences that may seem important to us may be completely ignored. While at times they may seem hypersensitive, at other times seeming to be extremely distractible, yet at other times being overly focused on an activity or on self-stimulation. They may find human contact stressful at times, or show an unusual focus in their sensory experiences, such as an exaggerated interest in smell, or in rhythmic motion.

Emotion
All of the confusion experienced by the child can make the world a frightful place. Difficulties in understanding and articulating their own emotions, or those of others, may cause your child's response in some situations to appear to be inappropriate. Emotional outbursts are common and it may be difficult for them to regain control. Our response to these outbursts may increase their confusion, frustration and anger. These outbursts may result in a child trying to hurt themselves or others.