One of the most common questions we hear is "what are the physical characteristics of autism?" It's a legitimate question, and one worth exploring. But we feel caution is in order before we answer.

It must be noted that it is impossible to diagnose autism based on someone's appearance. At the same time, it's impossible to rule out autism based on how someone looks. But with that caveat, it is clear that many people along the autism spectrum exhibit similar physical traits.

Among these common physical characteristics of autism are:

• poor facial muscle tone

• bruises or calluses caused by repetitive behaviors such as ear slapping or head banging

• impaired motor skills

• tactile sensitivity -- finding common physical activities such as washing or touching the floor with one's feet as painful or distressing