The physical characteristics of autism vary greatly from person to person. Most often, it is impossible to tell that someone has autism until you try to communicate with that person. It may then become abundantly clear that the person has Autism or some other pervasive developmental disorder.
Outward Signs of Autism
Autism and other pervasive developmental disorders (PDD) mainly affect a person's ability to communicate and interact socially. Those with Autism and PDD find social interaction and communication difficult. They may segregate themselves from others or engage in unusual behaviors.
Certain behaviors may be the only outward sign that a person has Autism. These behaviors can involve repetitive actions, such as stacking blocks over and over again, or they might be a fascination with spinning or flashing objects. Some autistics may have an inappropriate attachment to a specific object, like a toy train. Moving this object or taking it from the child will result in a severe tantrum.
Other Physical Signs
While most autistic behavior involves inability to sustain a conversation, inappropriate language and other verbal problems, there are occasionally some physical manifestations. Those who have Autism may have low facial muscle tone. This lack of muscle tone makes it difficult to smile, laugh and make eye contact. Since the causes of Autism are unknown, it's impossible to say if low muscle tone is a contributing factor or a symptom.
Some autistics may have large eyes, due to excessive pupil dilation. They may have pale skin from staying indoors.
Autistics often make repetitive motions, most commonly ear or hand flapping. In some instances, the repetitive motion is finger drumming or repeatedly tapping the forehead. In rare and extreme cases, the repetitive motion my involve head banging.
Autistics occasionally exhibit rigid behavior and an unwillingness to move. If forced to deviate from their normal patterns and routines, they become agitated and may throw a temper tantrum.
Other characteristics of autism include impaired motor skills. Autistics may have trouble with their gross or fine motor skills. Gross motor skills refers to larger activities, such as rolling over, sitting up, standing up and walking, while fine motor skills govern the ability to manipulate objects with the hands and control movements.
Moderate problems with gross motors skills can lead to the inability to walk normally. An autistic may have a short, stumbling gait or an uneven gait. Some autistics toe walk, placing all their weight on the toes. This leads to unusual muscle tone in their lower legs.
In the majority of cases, it's very difficult to spot an autistic simply by observing physical appearance for a short period of time. Subtle, repetitive behaviors may become obvious over longer periods of observation.
In the early history of autism, the condition was believed to be a type of schizophrenia, because of abnormal seratonin levels in patients.
Autism types range in severity, with some cases obvious by the age of three and some that remain undiagnosed until adulthood. Learn about the five major autism types on the autism spectrum.