Autism, or autism spectrum disorder (ASD), is a developmental disability caused by differences in the brain. It is a spectrum disorder, which means that it affects individuals differently and to varying degrees. People with ASD often have problems with social communication and interaction, and restricted or repetitive behaviors or interests. Some of the signs and symptoms of ASD include:

• Social communication and interaction skills: People with ASD often have difficulty with social communication and interaction. Examples of social communication and social interaction characteristics related to ASD can include avoiding or not keeping eye contact, not responding to name by 9 months of age, not showing facial expressions like happy, sad, angry, and surprised by 9 months of age, not playing simple interactive games like pat-a-cake by 12 months of age, using few or no gestures by 12 months of age, not sharing interests with others by 15 months of age, not pointing to show you something interesting by 18 months of age, not noticing when others are hurt or upset by 24 months of age, not noticing other children and joining them in play by 36 months of age, and not pretending to be something else, like a teacher or... .

• Restricted or repetitive behaviors or interests: People with ASD may have restricted or repetitive behaviors or interests. Examples of these behaviors can include repeating certain behaviors or routines, having a strong attachment to certain objects, having a strong interest in a specific topic, and having difficulty adapting to changes in routine or surroundings.

The exact cause of ASD is not known, but research suggests that it may be a combination of genetic and environmental factors. Some risk factors for ASD include maternal metabolic conditions such as diabetes and obesity, exposure to certain drugs or chemicals during pregnancy, and untreated phenylketonuria (PKU) and rubella (German measles) .

It is important to note that while some people without ASD might also have some of these symptoms, for people with ASD, these characteristics can make life very challenging.