The symptoms of one person with autism can be very different from the symptoms of another person with autism. Health care providers think of autism as a spectrum disorder—which means that there is a range of similar features in different people with the disorder.1
One person with autism may have mild symptoms, while another may have more serious symptoms, but they both have autism spectrum disorder (ASD).
Despite the range of possible symptoms, there are certain actions and behaviors that are common in ASD and could signal that a child is on the autism spectrum. Parents and caregivers who notice these "red flags" should speak to their child's health care provider about autism and screening the child for ASD.
In general, the main signs and symptoms of ASD relate to:
Communication and interactions with other people
Routines or repetitive behaviors, sometimes called stereotyped (pronounced STER-ee-uh-tahypt) behaviors
Health care providers organize some noticeable symptoms of autism into "red flags" to help parents and caregivers know what to look for as children grow and develop. These red flags are listed below.
Does not respond to his/her name by 12 months of age
Cannot explain what he/she wants
Doesn't follow directions
Seems to hear sometimes, but not other times
Doesn't point or wave "bye-bye"
Used to say a few words or babble, but now does not
Doesn't smile when smiled at
Has poor eye contact
Seems to prefer to play alone
Gets things for him/herself only
Is very independent for his/her age
Seems to be in his/her "own world"
Seems to tune people out
Is not interested in other children
Doesn't point out interesting objects by 14 months of age
Doesn't like to play "peek-a-boo"
Doesn't try to attract his/her parent's attention
Gets "stuck" doing the same things over and over and can't move on to other things
Shows unusual attachments to toys, objects, or routines (for example, always holding a string or having to put on socks before pants)
Spends a lot of time lining things up or putting things in a certain order
Repeats words or phrases (sometimes called echolalia [pronounced ek-oh-LEY-lee-uh])
Doesn't play "make believe" or pretend by 18 months of age
Has odd movement patterns
Doesn't know how to play with toys
Does things "early" compared to other children
Walks on his/her toes
Doesn't like to climb on things such as stairs
Doesn't imitate silly faces
Seems to stare at nothing or wander around with no purpose
Throws intense or violent tantrums
Is overly active, uncooperative, or resistant
Seems overly sensitive to noise
Doesn't like to be swung or bounced on his/her parent's knee, etc.
You can find age-specific milestones on the Centers for Disease Control and Prevention website Learn the Signs. Act Early. If your child does not meet developmental milestones, talk to his or her health care provider about screening for ASD.
Note about these red flags:
Some of these red flags apply only at certain ages, so consider what is typical for other children your child's age.
Some red flags are more strongly associated with autism than others.
If your child shows any red flags for autism, talk to his or her health care provider.
Citations
Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. (2013). American Psychiatric Association: Washington, DC.
Johnson CP, & Myers SM; American Academy of Pediatrics Council on Children with Disabilities. (2007). Identification and evaluation of children with autism spectrum disorders. Pediatrics, 120(5), 1183-1215.