The National Institutes of Health (NIH) explains that developmental disabilities are differences that are often present at birth that eventually affect a person’s physical, intellectual, and/or emotional development. A child with a developmental disability may begin prior to the age of 18, and result in differences in their ability to perform certain skills, including learning, reasoning, and problem solving that affect their social and life skills.

The broader category of developmental disabilities encompasses individual’s intellectual and/or physical challenges. The term DD refers to both intellectual and other disabilities noted below.

Nervous system. Nervous system disorders affect how an individual’s brain, spinal cord, and nervous system function in a manner that affects intelligence and learning, behavioral disorders, speech or language difficulties, seizures, and trouble with movement. Cerebral palsy, Down syndrome, Fragile X syndrome, and autism spectrum disorders (ASDs) are examples of IDDs related to problems with the nervous system.

Sensory system. Sensory system disorders impact a person’s senses, which includes the ability to see, hear, touch, taste, and smell. It also affects how a person’s brain processes or interprets information from the senses. Preterm infants and infants exposed to infections, such as cytomegalovirus, may experience difficulty with seeing and/or hearing. Individuals with an autism spectrum disorder can find touching, bright lights, food textures, loud noises, or crowds challenging.

Metabolism. Metabolism refers to how the body breaks down food during digestion that affect energy and growth. Metabolic problems can affect the body’s ability to function properly. Phenylketonuria (PKU) and congenital hypothyroidism are examples of metabolic conditions that can lead to IDDs.

Degenerative Disorders. An individual born with a degenerative disorder may appear typical when they are born, but may eventually encounter disruptions in their skills, abilities, and functions. Sometimes degenerative disorders are not detected until adolescence or adulthood. Degenerative disorders can also occur due to other conditions, such as untreated metabolic disorders.

The exact definition of developmental disability, and different types or categories of developmental disabilities, can vary depending upon the information source. For example, the Individuals with Disabilities Education Act (IDEA), a law to ensure that children with disabilities in the U.S. receive educational services, defines developmental disabilities conditions differently than the Social Security Administration (SSA) which provides services and support for these individuals. Sometimes health providers and researchers use different descriptions, as well.

Visit IDEA definitions disability at www.parentcenterhub.org/disability-landing. For information about SSA and disabilities, visit www.ssa.gov/planners/disability. March is developmental disabilities month. For more information, visit www.nacdd.org.