Symptoms and Signs

The symptoms of ASD typically fall into three core categories: difficulties with social interaction, communication challenges, and frequent repetitive behavior. However, as ASD is a spectrum disorder, it is important to remember that all symptoms can vary greatly in terms of type, number, and severity depending on the person affected.

The symptoms of ASD that appear most often and across all types of ASD are those in the social interaction category. People with ASD, both as young children and as adults, typically have trouble interacting with and relating to others. They are often unsure how to interpret and understand other people’s feelings or how to see things from someone else’s point of view, and in turn can have difficulty both expressing and controlling their own emotions. Social interaction challenges commonly appear as a lack of interest in others, unusual difficulty learning how to take turns and share, or emotional outbursts.

Communication challenges can apply to both verbal and non-verbal communication. Some people with ASD have no difficulty speaking, others speak very little or not at all. Still others can use language in unusual ways, such as repeating what they hear rather than responding to it (a condition known as echolalia), and some even develop precocious language skills and unusually large vocabularies. In terms of non-verbal communication, people with ASD often have difficulty both interpreting and exhibiting typical body language, facial expressions, and gestures.

Finally, engaging in repetitive behavior is usually one of the most visible symptoms of ASD. Physically, this symptom manifests itself as a tendency to perform repetitive movements or actions, like hand-flapping, rocking, and arranging and re-arranging objects, but it can also appear in more psychological ways. These include the development of intense preoccupations, such as a fixation on how certain machines function, and a strong affinity for routines, such as always doing the same things in the same order before going to bed. Sometimes, people with ASD develop routines that seem unnecessary or unusual but that are very important to them, like needing to look in every window when walking past a building.

ASD begins before the age of three; the symptoms of the disorder may become apparent at any time during that period. For a young child with ASD, early detection and intervention can make a huge difference in his or her development, so parents and caregivers are encouraged to watch out for the following “red flag” warning signs:

By six months of age: no big smiles or similar expressions.
By 12 months of age: no signs of responding to their name, no babbling, no interactive gestures such as pointing, waving, or reaching for objects.
By 16 to 18 months: no use of words, no “pretend” game play (such as pretending to “feed” a doll).
By 24 months: no meaningful, two-word phrases.
At any age: apparent loss of speech or social skills at any time, avoidance of eye contact, preference for playing alone, development of compulsions or rituals, lack of response to parents’ attempts to play, heightened sensitivity to certain sounds or lights.

If a child displays any of these signs, parents and caregivers are strongly encouraged to seek an evaluation from their pediatrician, family doctor, or other qualified health professional.

This Web site provides general educational information only. It is not intended to be, and should not be used as, a substitute for medical treatment or diagnosis by a health care professional. You should not assume that information on a particular topic on the Web site is complete or up to date. You should never disregard or delay seeking medical advice because of what you have read on this Web site.