Genre: Information/Explanation

As illustrated by the graph on the left , the basic symptoms of autism are often accompanied other medical conditions and challenges . These , too , can vary widely in severity . While autism is usually a life-long condition , all children and adults benefit from interventions , or therapies , that can reduce symptoms and increase skills and abilities . Although it is best to begin intervention as soon as possible , the benefits of therapy can continue throughout life . Social Challenges Typically developing infants are social by nature . They gaze at faces , turn toward voices , grasp a finger and even smile by 2 to 3 months of age . By contrast , most children who develop autism have difficulty engaging in the give-and-take of everyday human interactions . By 8 to 10 months of age , many infants who go on to develop autism are showing some symptoms such as failure to respond to their names , reduced interest in people and delayed babbling . By toddlerhood , many children with autism have difficulty playing social games , do n't imitate the actions of others and prefer to play alone . They may fail to seek comfort or respond to parents' displays of anger or affection in typical ways . It is common – but not universal – for those with autism to have difficulty regulating emotions . This can take the form of seemingly " immature " behavior such as crying or having outbursts in inappropriate situations . It can also lead to disruptive and physically aggressive behavior . The tendency to " lose control " may be particularly pronounced in unfamiliar , overwhelming or frustrating situations . Frustration can also result in self-injurious behaviors such as head banging , hair pulling or self-biting . Communication Difficulties By age three , most children have passed predictable milestones on the path to learning language . One of the earliest is babbling . By the first birthday , most typically developing toddlers say a word or two , turn and look when they hear their names , point to objects they want or want to show to someone ( not all cultures use pointing in this way ) . When offered something distasteful , they can make clear – by sound or expression – that the answer is " no . " By contrast , young children with autism tend to be delayed in babbling and speaking and learning to use gestures . Some infants who later develop autism coo and babble during the first few months of life before losing these communicative behaviors . Others experience significant language delays and do n't begin to speak until much later . With therapy , however , most people with autism do learn to use spoken language and all can learn to communicate . Many nonverbal or nearly nonverbal children and adults learn to use communication systems such as pictures ( image at left ) , sign language , electronic word processors or even speech-generating devices . When language begins to develop , the person with autism may use speech in unusual ways . Some have difficulty combining words into meaningful sentences . They may speak only single words or repeat the same phrase over and over . Some go through a stage where they repeat what they hear verbatim ( echolalia ) . Some mildly affected children exhibit only slight delays in language or even develop precocious language and unusually large vocabularies – yet have difficulty sustaining a conversation . Some children and adults with autism tend to carry on monologues on a favorite subject , giving others little chance to comment . In other words , the ordinary " give and take " of conversation proves difficult . Some children with ASD with superior language skills tend to speak like little professors , failing to pick up on the " kid-speak " that 's common among their peers . Conversely , someone affected by autism may not exhibit typical body language . Facial expressions , movements and gestures may not match what they are saying . Their tone of voice may fail to reflect their feelings . Some use a high-pitched sing-song or a flat , robot-like voice . This can make it difficult for others know what they want and need . This failed communication , in turn , can lead to frustration and inappropriate behavior ( such as screaming or grabbing ) on the part of the person with autism . Fortunately , there are proven methods for helping children and adults with autism learn better ways to express their needs . As the person with autism learns to communicate what he or she wants , challenging behaviors often subside . ( See section on Treatments . ) Repetitive Behaviors Unusual repetitive behaviors and / or a tendency to engage in a restricted range of activities are another core symptom of autism . Common repetitive behaviors include hand-flapping , rocking , jumping and twirling , arranging and rearranging objects , and repeating sounds , words , or phrases . Sometimes the repetitive behavior is self-stimulating , such as wiggling fingers in front of the eyes . The tendency to engage in a restricted range of activities can be seen in the way that many children with autism play with toys . Some spend hours lining up toys in a specific way instead of using them for pretend play . Similarly , some adults are preoccupied with having household or other objects in a fixed order or place . It can prove extremely upsetting if someone or something disrupts the order . Along these lines many children and adults with autism need and demand extreme consistency in their environment and daily routine . Slight changes can be extremely stressful and lead to outbursts Repetitive behaviors can take the form of intense preoccupations , or obsessions . These extreme interests can prove all the more unusual for their content ( e.g. fans , vacuum cleaners or toilets ) or depth of knowledge ( e.g. knowing and repeating astonishingly detailed information about Thomas the Tank Engine or astronomy ) . Older children and adults with autism may develop tremendous interest in numbers , symbols , dates or science topics . Associated Medical Conditions Thanks to donor support , Autism Speaks continues to fund research into the causes and treatment of the medical conditions associated with ASD . You can explore these studies here . This research is reflected in the comprehensive care model at the heart of our Autism Treatment Network ( ATN ) clinics . To find out if there is an ATN clinic close to you , click here . For in depth information on medical conditions , please see our website's related pages : " Treatments for Associated Medical Conditions " and " What Treatments are Available for Speech , Language and Motor Impairments , " in addition to the information below . Genetic Disorders Some children with autism have an identifiable genetic condition that affects brain development . These genetic disorders include Fragile X syndrome , Angelman syndrome , tuberous sclerosis and chromosome 15 duplication syndrome and other single-gene and chromosomal disorders . While further study is needed , single gene disorders appear to affect 15 to 20 percent of those with ASD . Some of these syndromes have characteristic features or family histories , the presence of which may prompt your doctor to refer to a geneticist or neurologist for further testing . The results can help guide treatment , awareness of associated medical issues and life planning . Gastrointestinal ( GI ) Disorders GI distress is common among persons with autism , and affects up to 85 percent of children with ASD . These conditions range in severity from a tendency for chronic constipation or diarrhea to inflammatory bowel disease . Pain caused by GI issues can prompt behavioral changes such as increased self soothing ( rocking , head banging , etc ) or outbursts of aggression or self-injury . Conversely , appropriate treatment can improve behavior and quality of life . Please see our treatment section on " Gastrointestinal Disorders . " It includes discussion of popular dietary interventions . Thanks to donor support , Autism Speaks continues to fund research into causes and treatments . Seizure Disorders Seizure disorders , including epilepsy , occur in as many as 39 percent of those with autism . It is more common in people with autism who also have intellectual disability than those without . Someone with autism may experience more than one type of seizure . The easiest to recognize is the grand mal , or tonic-clonic , seizure . Others include " petit mal " seizures ( when a person temporarily appears " absent " ) and subclinical seizures , which may be apparent only with electroencephalogram ( EEG ) testing . Sleep Dysfunction Sleep problems are common among children and adolescents with autism and may likewise affect many adults . For more information and helpful guidance , see our ATN Sleep Strategies Tool Kit ( available for free download ) . Sensory Processing Problems Many persons with autism have unusual responses to sensory input . They have difficulty processing and integrating sensory information , or stimuli , such as sights , sounds smells , tastes and / or movement . They may experience seemingly ordinary stimuli as painful , unpleasant or confusing . ( Explore our donor-funded research on causes and treatments here . ) Some of those with autism are hypersensitive to sounds or touch , a condition also known as sensory defensiveness . Others are under-responsive , or hyposensitive . An example of hypersensitivity would be the inability to tolerate wearing clothing , being touched or being in a room with normal lighting . Hyposensitivity can include failure to respond when one's name is called . Many sensory processing problems can be addressed with occupational therapy and / or sensory integration therapy . ( More information on these therapies , here . ) Pica