Sensory Processing Disorder (SPD) is a condition in which the brain has difficulty receiving and responding to information that comes in through the senses. It is also known as sensory integration dysfunction. SPD is not currently recognized as a distinct medical diagnosis, and there is some debate among doctors about whether it is a separate disorder or a symptom of other disorders such as autism spectrum disorder, attention deficit and hyperactivity disorder, anxiety, etc.. Some doctors believe that SPD is a diagnosis for things that could be explained as common behavior for children, while others say that some children are just highly sensitive.

SPD can affect anyone, but children are more likely than adults to have it. Symptoms of SPD include being oversensitive to things in the environment, such as common sounds that may be painful or overwhelming, or the light touch of a shirt that may chafe the skin. Other symptoms include impaired coordination, bumping into things, being unable to tell where limbs are in space, and being hard to engage in conversation or play.

The causes of SPD are not yet fully understood, but research suggests that it may be inherited. Studies have found a significant difference between the physiology of children with SPD and children who are typically developing, and between children with SPD and those with ADHD. The sympathetic and parasympathetic nervous systems may also play a role in SPD.

While SPD is not currently recognized as an official medical diagnosis, it is a way to identify those who may need some extra attention in this area. Treatment for SPD may include occupational therapy, sensory integration therapy, and other therapies that help individuals learn to process sensory information more effectively.