Sensory Processing Disorder is defined as a condition in which the brain has trouble receiving and responding to information that comes in through the senses.
Some of the symptoms of Sensory Processing Disorder include getting tired easily, discomfort while climbing, poor posture control and strength, withdrawing from light, withdrawing from touch, gagging, refusing to eat certain foods, disliking hair washing, brushing teeth and getting nails cut, avoidance of messy things like dirt and lotion/shaving cream, etc, and an oversensitivity to sounds or visual stimuli.
Symptoms of Sensory Processing Disorder can usually be seen early, sometimes in infancy, but almost always by preschool. Parents should look for things like a child screaming or crying when they are getting their clothes changed, crying when being dried off with a towel, being afraid to wash their hands, etc.
Not everyone with autism has sensory Processing Disorder, however, many have a lot of the symptoms and SPD is very common among autistics. There are still many children that have Sensory Processing Disorder that do not have autism, though, and some doctors believe that many children with ADD and ADHD actually have SPD. There is also no evidence to suggest that Sensory Processing disorder is more common in one gender over the other. It seems that both genders could be affected equally.
If you think your child may have Sensory Processing Disorder, you should let their pediatrician know. They can refer you to a developmental pediatrician for an evaluation.