There are many different combinations of symptoms of autism spectrum disorders (ASD). The severity of ASD can also vary from person to person. Most symptoms will appear before 3 years of age with most showing between 18 to 24 months. They may appear at this age because children grow and change rapidly at this stage.

ASD may cause a loss of milestones that were already reached. It can also prevent or slow new milestones. General developmental problems include:

• Problems with social skills
• Problems with communication
• Repetitive behaviors or unusual activities
• Problems with how the brain receives and responds to sensations around them (processing sensory information)

ASD can cause a wide range of behaviors such as:

• No eye contact
• No response to name
• Not imitating others
• Little or no speaking
• Wants to play alone
• Little interaction or listening to others
• Aggression
• Self-destructive behavior
• Hyperactivity
• Tantrums—can be with little or no prodding
• Use of language in unusual ways
• Repetitive behaviors—may spend hours with a single activity over and over again such as rocking or flapping a hand
• Stare at certain objects for a long time
• Overreaction to small changes in their environment
• Sensitivity to sound, smell, taste, sights, and touch
• Feel pain from a light touch, but ignore more severe pain
• Experience sounds as colors, and touches as sounds

Trust what you feel. Call your child's doctor if you have any worries about your child's development. Children and their families may benefit from early, intense intervention.